rusn158e

News from Rohde & Schwarz

Network analysisnow up to 8 GHz

Digital audio broadcasting– new transmitters for band III and L band

Digital scanning direction findersdetect broadband and short-term signals

1581998/I I

News from Rohde & Schwarz Number 158 (1998/I I)

Number 158 1998/II Volume 38

“Double frequency and benefit” is the slogan forthe ZVR family of network analyzers. The two newmembers ZVCE and ZVC extend the frequencyrange from 4 GHz to 8 GHz, opening up a wide range of new applications (see article onpage 4). Photo 42 126

Dr Olaf Ostwald; Vector Network Analyzers ZVCChristian Evers Double frequency and benefit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

Dr Klaus Gresser; Digital Radio Testers CTS65 and CTS60Gottfried Holzmann All-rounders in servicing GSM and DECT mobile phones . . . . . . . . . . . . . . . . . . . . .7

Dr Lothar Tschimpke Multifunction Module AMV for Test Systems TSA and TSUAnalog measurements in module production now even more efficient . . . . . . . .10

Rainer Steen; Cornelius Heinemann; DAB Transmitters NA6… and NL6…Peter H. Frank Digital audio broadcasting – reliable and economical . . . . . . . . . . . . . . . . . . . . . . .13

Dr Rolf Springer; Vehicle Location System VELOSDr Lothar Schirm DGPS-supported vehicle location with fast radio data . . . . . . . . . . . . . . . . . . . . . . .16

Klaus Friede; Antenna Systems AC090, AC120, AC180, AC300Ludwig Nielsen Radiomonitoring in microwave range up to 40 GHz . . . . . . . . . . . . . . . . . . . . . . . .18

Franz Demmel; Digital Scanning Direction Finders DDF0xSWilhelm Genal; Ulrich Unselt Fast direction finding of broadband and short-term signals. . . . . . . . . . . . . . . . . . .21

Klaus Kundinger Production test of RF modules with Universal Test System TSU, Radiocommunication Service Tester CMS and EMC test cell. . . . . . . . . . . . . . . . . .24

Albert Winter Applications in and around fading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Articles

Application notes

Thomas A. Kneidel COM2000 – the functional software tool for shortwave communication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Software

Dr Klaus H. Blankenburg Correct usage of quantities, units and equations (II) . . . . . . . . . . . . . . . . . . . . . . . . . .30

Refresher topic

3News from Rohde & Schwarz Number 158 (1998/I I)

Published by ROHDE & SCHWARZ GmbH & Co. KG Mühldorfstraße 15 D -81671 MunichTelephone (0 89) 41 29-0 · international (+49 89) 41 29-0 · Editors: H. Wegener and G. Sönnichsen(German) · English translation: Dept. 5CL4 · Photos: S. Huber · Artwork: N. Hofmann · Circulation100 000 four times a year · ISSN 0028-9108 · Supply free of charge · State company or position ·Printed in the Federal Republic of Germany by peschke druck, Munich · Reproduction of extracts permitted if source is stated and copy sent to R & S Munich

Imprint

Panorama

Kurt Lainer Signal Generators SME03A and SMIQ03A – two milestones on the way to faster measurements . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Johann Maier Twenty-four complete mobile-radio coverage measurementsystems for China . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Erwin Böhler Rohde & Schwarz – a partner for in-production testing of mobile phones. . . . .34

Manfred Stecher 200-A Four-Line V-Network ENV4200 for measuring RFI voltages at high currents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35

Hans-Dieter König; Helmut Hingrainer Design 2000, the new enclosure system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Regular features

Paul Dambacher Patent: Method and equipment for transmission of digital sound signals in terrestrial broadcasting networks . . . . . . . . . . . . . . . . . . . .15

Volker Janssen In brief: EMC Asia 97 – debut in Singapore . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Reference: Valuables packed safely –Knürr-Mechanik für die Elektronik AG. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Roland Minihold Test hint: Reducing time to test GSM base stations . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Booktalk: Digital terrestrial television broadcasting . . . . . . . . . . . . . . . . . . . . . . . . . .31

Information in print . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Newsgrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Press comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

Christian Rockrohr Final article: Airspace safety and Austro Control –an excellent combination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

GSM + DECT – Digital Radio Tester CTS65 canhandle both standards, which makes it a veryeconomical tester for servicing, marketing andproducing mobile and cordless phones (page 7).

Photo 43 115/1

4 News from Rohde & Schwarz Number 158 (1998/I I)

To date the ZVR family consisted ofthree members: unidirectional NetworkAnalyzer ZVRL and bidirectional Analyzers ZVRE and ZVR [1]. These instruments allow complex transmissionand reflection measurements (magni-tude and phase) on two-port DUTs from10 Hz, 9 kHz or 300 kHz, dependingon the analyzer’s configuration level.The upper frequency limit of these ana-lyzers is 4 GHz. Now the two newmodels ZVCE and ZVC (FIG 1) extendthis upper frequency limit by a factor of two, making it possible to measuresatellite components in the frequencyrange up to 8 GHz for example. Thelower frequency limit of the new ana-lyzers is 20 kHz (FIG 2). Three-channelNetwork Analyzer ZVCE uses 12-termTOSM calibration for bidirectional

two-port measurements, while AnalyzerZVC with four receive channels also allows use of modern 7-term calibrationtechniques such as TOM, TNA and

TOM-X and thus offers solutions to reallycomplicated measurement problems indevelopment and production.

All five members of the ZVR family offerexcellent measurement accuracy, widedynamic range and high measure-ment speed in addition to their largefrequency range. The instruments set up on an IBM PC-compatible computerkernel with the usual interfaces and peripherals. Results can be computedand converted by a variety of functionsand displayed on the large colour monitor. They can then be handled onthe network analyzer using conven-tional word processing and spread-sheet programs to create informativedocuments together with comments.

The versatility of the ZVR family of network analyzers is demonstrated bya list of typical applications rangingfrom antennas through to Z-parametermeasurements (blue BOX).

All models of the ZVR family excel in a variety of special features relating totest procedures, data evaluation func-tions and display modes. For example,implicit verification is performed dur-ing calibration (TOM) of bidirectionalfour-channel Network Analyzers ZVRand ZVC by checking the consistency

Articles

Vector Network Analyzers ZVC

Double frequency and benefitThe ZVR family of network analyzers is growing fast. The two new members ZVCEand ZVC extend the frequency range of the analyzers from 4 GHz to 8 GHz,opening up a wide new range of applications.

Typical application Special feature of ZVR family

Antennas for GSM and GPS Fast data transfer by DDE

Antenna sockets Optional four-port adapter [2] without further accessories

Audio systems Lower frequency limit 10 Hz

Automotive engineering Measurements on frequency-converting immobilizers

Cables Logarithmic displays, phase unwrap function

CATV amplifiers Multiport measurements

CATV transposers Frequency-converting measurements with wide dynamic range

Circulators Three-port adapter with electronic switch

Documentation Data transfer to Word, Excel and CAE programs

GSM, base station filters Segmented sweep without speed reduction

GSM/DECT, SMD amplifiers Patented calibration methods for SMD adapters

GSM, ceramic filters Fast sweep times for realtime adjustment

GSM, SAW filters Virtual transformation for complex impedances

Multiports such as couplers, Four-port adapters with electronic switches,switches and filter banks up to four separate, individually calibrated signal paths

On-wafer measurements TOM-X calibration to eliminate crosstalk [3]

Pagers Measurements with extremely low input levels

Quartz production Fast detection of phase zero crossings

Satellite communication Extremely wide linear range

Z-parameter measurements Complex conversion of Z-parameters

FIG 1 New addition to ZVR family: Vector Net-work Analyzer ZVC for frequencies up to 8 GHz

Photo 43 177


of the calibration results with the characteristic data of the calibrationstandards. In this way the analyzer iseven capable of distinguishing anopen-circuit test port from a port cor-rectly terminated with a standard open.Any calibration errors are automati-cally detected immediately after cali-bration. The user is warned and cancorrect to avoid measurement errors.

In multiport applications too, the useris supported by highly convenient calibration routines. Such applicationsnormally require two-port calibration of many different signal paths. Herethere are big time-savings because inmodern 7-term methods only six (TOM)or four (TNA) connections have to bemade in contrast to the classic TOSM12-term method requiring four differentcalibration standards and eight con-nections.

A particular advantage in the evalua-tion of results is that conversion and for-matting for the test trace and markervalues can be selected completely independently of each other. For example, return loss may be selectedfor the test trace, and the correspond-ing phase or complex impedance of theDUT for markers. Using all four displaychannels, which can be decoupledfrom each other, up to eight measuredquantities can then be displayed simul-taneously. Backed up by this compactdisplay, the user can see at a glanceany interactive effects in complex alignments.

The network analyzers offer furtherinteresting features in phase and delaymeasurements. These include the phaseunwrap function, which allows phasemeasurements beyond 180°. This enables phase response analysis onDUTs like cables or multisection filterswithout the disturbing effect of phasediscontinuities. The analyzers offer twofunctions for group delay measure-ment. First there is the conventionalstep aperture, where the aperture isset as an integer multiple of the spacingbetween the frequency points. The

second function is frequency aperture,where a user-defined frequency valuecan be entered independent of the frequency grid. This guarantees a clearly defined aperture that is inde-pendent of the frequency spacing and exactly maintained, even with logarithmic sweeps. For group delaymeasurements too, the analyzers of theZVR family thus provide a high degreeof protection against operating errorsand at the same time very convenientdisplay of results.

The phase delay function offers additional measurement capabilities. It determines total phase deviation acrossthe selected frequency range. It may be up to several thousand degrees de-pending on the DUT’s electrical length.Relative measurement inaccuracy is less than 0.1‰ thanks to theanalyzers’ high phase accuracy of typ-ically 0.1°. This method is particularlysuitable for highly precise measurementof electrical length on low-dispersionDUTs like cables. Alternatively the analyzer can indicate the phase delayor the electrical or mechanical length of the DUT.

Arbitrary zoom in Cartesian chartsand especially in Smith charts makes itpossible to expand not only the centerof the chart but for instance also theshort-circuit and open-circuit points. Sothe complex impedance of resonators

or transistors can be displayed withhigh resolution for any part of the Smithchart. Scaling, especially in Cartesiancharts, is elegantly solved with the minimum and maximum scaling func-tions. The intelligent graticule alwaysyields even divisions, which greatly simplifies chart evaluation.

The high measurement accuracy andoutstanding performance especially of the bidirectional four-channel Analyzers ZVR and ZVC, even with“awkward” DUTs, is based on specialcalibration methods, patented by Rohde & Schwarz, such as TRM, TNAand TOM-X [1; 3] and the AutoKal automatic calibration function. AutoKaloffers the advantage that the asso-ciated adapter need not be connectedand disconnected for each calibrationbut can remain permanently connectedto the analyzer test ports (direct or via cable). Automatic calibration iscompleted in about 20 s.

The high versatility of the analyzers ofthe ZVR family is further enhanced by a variety of options and accessories.Measurements on three-ports or four-ports, eg diplexers, circulators, switches,directional couplers or filter banks, canbe carried out fast and conveniently bymeans of the three-port adapter, thetwo four-port adapters and the extrainputs four-port option [2]. Switch-over between up to four ports of a DUT is effected fast and reproduciblyby means of electronic switches. Theanalyzer always operates at full speed,offering up to four separate, simultane-ous calibrations for the different signalpaths. No loading or switching timesneed to be taken into account for thecalibrations.

In conjunction with the virtual em-bedding networks option, special calibration methods [3] such as TNAand TOM-X allow the effect of parasiticsto be reduced, which occur with testadapters, test beds or test probes. Thisenables production-oriented optimiza-tion of test equipment exclusively interms of mechanical aspects, repro-

Articles

FIG 2 Frequency ranges of ZVR family

9 kHz

10 Hz

300 kHz

20 kHz 4 GHz 8 GHz

ZVR + ZVREActive Test Set

ZVR + ZVRE + ZVRLPassive Test Set

ZVR + ZVRE + ZVRLExternal Measurements

ZVC + ZVCEActive Test SetZVC + ZVCE

Active Test Set


ducibility, service life and reliability.Electrical quality may be neglected as itis determined rapidly and accuratelyduring calibration and then optimized,ie computed, with high precision. More-over, the calibration standards em-ployed in TNA are easy to generateand to use since requirements made ontheir electrical data are low.

Another strong point of the ZVR familyis measurements on frequency-con-verting DUTs, which cover a widerange of important applications. Note-worthy in this context is fast measure-ment of the image rejection of single-sideband mixers [4]. DUTs such as tuners or front-ends, which performmultiple frequency conversion of the input signal, can be measured direct

and conveniently with the arbitraryfunction of this option. FIG 3 shows thetest setup for a double frequency-converting receiver front-end. NetworkAnalyzers ZVR in conjunction with advanced Rohde & Schwarz signalsources, eg Microwave Signal Gen-erator SMP, offer fast remote controlcapability (IEC/IEEE+TTL) using specialTTL signals exchanged via rear-panelconnectors of the two instruments. This allows the conversion losses of a

double frequency-converting DUT to be measured and displayed (FIG 4) in quasi-realtime. It is also possible tomake group delay measurements onfrequency-converting DUTs, eg mixersor tuners, if an external reference mixeris connected to the two optional rear-panel connectors. Nonlinear measure-ments too, like determining the com-pression point of active DUTs, can be carried out simply and virtually in realtime [5].

Application notes are available on thetopics of data transfer, group andphase delay measurements, measure-ment inaccuracy, AutoKal, multiportand frequency-converting measure-ments and are obtainable from all Rohde & Schwarz sales offices.

Dr Olaf Ostwald; Christian Evers

REFERENCES

[1] Ostwald, O.; Evers, C.: Vector Network An-alyzer Family ZVR – To the heart of the chart.News from Rohde & Schwarz (1996) No. 150, pp 6–9

[2] Ostwald, O.: Fast S-parameter measurementson four-port devices. News from Rohde &Schwarz (1997) No. 155, p 16

[3] Ostwald, O.; Bednorz, T.: Troika – die ZVR-Familie: Vektorielle Netzwerkanalyse schnell,präzise und komfortabel. Elektronik Praxis31 (1996) No. 3, pp 116–119

[4] Simon, J.: Measuring image rejection of single-sideband mixers. News from Rohde & Schwarz (1998) No. 157, p 18

[5] Ostwald, O.: New option for fast compres-sion-point measurements with Vector Net-work Analyzer ZVR. News from Rohde &Schwarz (1997) No. 154, p 33

Articles

Condensed data of Vector Network Analyzers ZVCFrequency range 20 kHz to 8 GHz

Measurement time 125 µs/point

Dynamic range >120 dB

Measurement bandwidths 1 Hz to 10 kHz (half-decade steps)and 26 kHz (full)

Amplitude uncertainty <0.2 dB, typ. <0.025 dB

Phase uncertainty <1°, typ. <0.2°

Calibration TOM, TRM, TRL, TNA, TOSM,TOM-X, AutoKal

Display 26 cm colour LCD

Number of pixels 640 x 480 (SVGA)

Remote control IEC 625-2 (SCPI 1994.0) or RS-232-C

Reader service card 158/01

FIG 3 Test setup for double frequency-convert-ing DUT (receiver front-end)

FIG 4 Measured conversion loss of double frequency-converting receiver front-end (super-imposed: definition table for this mode)

DUT(RF converter front-end)

2ff

Mixer 1 Mixer 2

200 MHz to 7 GHz 741 MHz

3.6 GHz8.141 to 14.941 GHz

1st LO (eg SMP) 2nd LO (eg SMP)

Port 1 Port 2

ZVC


The successful concept of Digital Radio-communication Testers CMD [1; 2] continues in the CTS family of servicetesters, which has now been completed.Multimode Tester CTS65 (FIG 1) offersthe user a wide range of functions in asingle unit for the following networks:GSM900 (Europe), GSM1800 (PCN,Europe), GSM1900 (PCS, USA), DECT Europe and DECT Latin America.This adds extra versatility to the provenapplications of CTS, which are at POS (point of sale), in servicing and theproduction of mobile phones.

The great ease of operation ofCTS60/65 via six softkeys on thecolour monitor has proven itself inCTS55 [3]. The main menu offers selec-tion of network standards GSM900,GSM1800, GSM1900 and DECT.With DECT it is possible to choose PP(portable part) or FP (fixed part) tests.An external keyboard can be connect-ed, if required, as with CTS55. Apartfrom the TFT colour display, an externalmonitor can alternatively be connectedvia the VGA interface. Intelligent menuguidance largely excludes incorrect entries.

Testing DECT telephones

DECT (digital enhanced cordless tele-communications) is now the establishedstandard for digital voice transmissionby cordless telephone also outside ofEurope. The sharp decline in prices andthe qualitative edge are driving analogsystems out of the market. In addition to the cordless phones application,DECT offers the possibility of covering

congested areas such as airports andrailroad stations, thus getting round bottlenecks in GSM networks. Fieldtrials are currently being conducted toinvestigate alternative linkup of privatehouseholds to the telephone network bymeans of DECT (wireless local loop,last mile). Ten frequency channels in the 1900 MHz band are reserved for

DECT, each channel allowing twelve simultaneous calls in TDMA (time divi-sion multiple access) operation. Thismeans that 120 simultaneous calls arepossible in a cell. DECT also uses TDD(time division duplex), in which callsare transmitted at a single frequency inboth directions but offset in time. DECTcells organize themselves, ie transmis-sion channels are selected so that thereis no interference with any neighbour-ing cordless telephone systems.

Digital Radio Tester CTS60/65 meas-ures DECT portable parts and DECTfixed parts. The DUT is switched to the test or loopback mode, causing the data received to be returned toCTS60/65 on the transmit channel.This mode is required for measuringBER, modulation parameters and fre-quency accuracy.

Articles

Digital Radio Testers CTS65 and CTS60

All-rounders in servicing GSM and DECT mobile phonesIn Digital Radio Tester CTS65, Rohde & Schwarz now offers a compact, favour-ably priced multimode service tester for GSM mobile phones and for cordlessphones to DECT standard. CTS60 is available for pure DECT applications.

FIG 1 Multimode Service

Tester CTS65 forGSM and DECT

systemsPhoto 43 115/3


The following parameters are deter-mined in DECT measurements:

The normal transmit power is the average power during transmit time.With DECT it is max. 250 mW, whichcorresponds to 24 dBm.

The power ramp verifies compliancewith specified timing parameters andpower ranges during transmission. Thegraphic display shows any abnormalconditions at a glance.

Frequency deviation during trans-mission is another graphic display allowing fast diagnosis of frequencysynthesis and modulation character-istics (FIG 2).

The frequency offset indicates inaccu-racy of the center frequency.

Frequency drift is a measure of centerfrequency change during transmission.

Display of maximum positive and negative modulation deviation verifiescompliance with specified modulationdeviation and enables adjustment ofdeviation.

The timing accuracy gives the percent-age deviation of the time frame fromthe specified figure of 10 ms.

Jitter is a measure of the irregularity ofthe time frame.

The packet accuracy measurement reveals if transmission of a PP starts ex-actly half a frame period after the FP.

The bit error rate (BER) is the ratio of er-rored bits received to all bits received.Unlike the foregoing, this is a receivermeasurement.

The frame error rate (FER) is anotherparameter indicating receiver quality. It covers completely lost frames andframes with at least 25% BER.

The echo test allows a rapid check of DUT loudspeaker and microphone

functionality. Voice signals sent by thePP to CTS60/65 are returned by thetester with a delay.

For each measurement, tolerances prescribed by ETSI are preset, but canbe changed by the user as required.Out-of-tolerance values are highlightedby the coloured display of results.Coloured display increases informationquality especially in the graphicalmeasurement menus for the powerramp and RF modulation and makesCTS60/65 a valuable instrument for efficient troubleshooting.

Another feature enhancing the practi-cality of CTS60/65 in servicing is theconfigurable auto test familiar fromCMD60/65. This allows user-definedcombination of test steps such as callsetup, power ramp, modulation, timingand BER measurements and call release(FIG 3). Measurement parameters andtolerances are freely configurable foreach of these test steps (FIG 4). The auto test further provides interactivecommands and conditional plus uncon-ditional loops. Despite this outstandingperformance, operation is extremelyeasy, making it as a rule unnecessary toconsult the manual. Test report printoutsprovide information on all settings,measured values and out-of-toleranceconditions.

Digital Radio Tester CTS65 incorporatesthe modules of CTS55 and in additiona DECT module similar to the one inCMD60. The DECT module not onlycontains all the required RF hardware

Articles

GSM DECT

CTS-B1 OCXO reference oscillator for CTS-B1 OCXO reference oscillator for enhanced accuracy of all enhanced accuracy of all frequency-related parameters frequency-related parameters

CTS-K7 GSM module test

CTS-K6 Remote control via RS-232-C CTS-K6 Remote control via RS-232-Cwith GSM application software for Windows

CTS-U56 Upgrade of CTS55 CTS-U65 Upgrade of CTS60to Multimode Tester CTS65 to Multimode Tester CTS65

Options for Digital Radio Testers CTS55/60/65

FIG 2 RF modulation menu

FIG 3 Free configuration of auto test

FIG 4 Configuration of single test step


(transmitter, signalling receiver and testreceiver) but also the signalling andmeasurement unit including the soft-ware. The blue BOX lists the availableoptions allowing application-oriented,cost-effective configuration of the digital radio testers. CTS55 is easily upgraded to CTS65 of course.

New test facilities in GSM modeAs with all mobile radio testers fromRohde & Schwarz, the GSM membersof the CTS family are continuously ex-panded to cover new applications [4].For example, new menus are providedfor the selection of different displaymodes in remote control; either thewindow with the current device statusor the remote-control commands to-gether with device and error status can be displayed. Baud rate, start, stopand parity bits can be user-configuredfor the RS-232-C interface.

Fast power measurement (approx. tenmeasurements per second) and the narrowband spectrum monitor makeCTS an ideal instrument for adjustingthe transmitter power and modulationof GSM mobile phones.

An interesting feature is the GSM application software included in theoptional remote control via RS-232-C.The software contains a configurableautomatic test sequence that runs on an external PC under Windows 3.1,Windows 95 and Windows NT. Parameters such as network used, type and extent of measurements as

well as tolerances can be selected by simple mouse clicks (FIGs 5 to 7).The straightforward measurement reportallows further evaluation and archivingof test data. Results can be exported toother programs via data filters.

Dr Klaus Gresser; Gottfried Holzmann

REFERENCES

[1] Mittermeier, W.: Digital Radiocommunica-tion Testers CMD65 and CMD80 – Multi-band and multimode testers for mobile-radiotelephones. News from Rohde & Schwarz(1997) No. 155, pp 6–8

[2] Maucksch, T.: Digital RadiocommunicationTester CMD60 – A favourably priced com-pact test set for series production of DECTmobiles. News from Rohde & Schwarz(1995) No. 149, pp 13–15

[3] Vohrer, M.: Digital Radio Tester CTS55 – All-in-one service tester for GSM, PCN andPCS mobile telephones. News from Rohde &Schwarz (1996) No. 152, pp 4–6

[4] Holzmann, G.: New measurement functionsin Digital Radio Tester CTS55. News fromRohde & Schwarz (1997) No. 155, p 33

Articles

Condensed data of Digital Radio Testers CTSGSM mode (CTS55/65) DECT mode (CTS60/65)

DUTs GSM900, GSM1800, FPs and PPs for DECT EuropeGSM1900 mobile phones and DECT Latin America

Modes quick test, loopback mode,manual test, manual test,auto test, auto test,module test, remote control via RS-232-Cremote control via RS-232-C

Functions synchronization, synchronization,location update, call setup call setup and release,and release, handover, echo testpower change, echo test

Test parameters power, power ramp, power, power ramp,phase/frequency error, demodulated frequency/offset/drift,timing accuracy, sensitivity modulation deviation, timing (BER, RBER, FER, RxLev, accuracy, jitter, packet accuracy, RxQual) sensitivity (BER, FER)

Reader service card 158/02FIG 5 Call setup (registration) with user inter-face of GSM application software

FIG 6 Configuration of measurements

FIG 7 Extract from measurement report


A partner for in-production testingChoosing a particular solution for in-production testing means choosing along-term partner. The integration of

solutions into a production line, the useof fixtures and programs absorb muchmore capital than the test system itself.So for a supplier of test solutions it is absolutely indispensable first to supporta variety of general production tests, ie in-circuit, functional and optical tests[1 to 3], secondly to possess the specialknow-how and technology for the appli-cation on hand (eg mobile radio com-munications), and thirdly to be able to

conceive complete systems/projectsright through to in-line production and to provide the required supportthroughout the world. In MultifunctionModule AMV, Rohde & Schwarz con-tinues to play its role as a pacemakerfor system solutions. The new measure-ment technology for the well-knownTSA and TSU families is not only an innovation in itself but also represents amilestone towards platform conceptsfor PCB testing (FIG 1).

Articles

Multifunction Module AMV for Test Systems TSA and TSU

Analog measurements in moduleproduction now even more efficientThe increasing density of components on PCBs coupled with the difficulty of accessing internal nodes via bed-of-nails fixture have put functional and finaltests at PCB level to the fore. Rohde & Schwarz meets this challenge with itsbrand-new analog measurement technology for in-production testing of modules.

Technology

Multifunction Module AMV (FIG 2) is a complete test system on a modulefor analog in-circuit and functional testsup to typically 1 MHz with associatedinterconnections and triggering. Themodule unites the functionality of seventest modules used up to now and twoexternal IEC/IEEE-bus units, but only requires two of the 13 slots in Universal

FIG 1 Multifunction Module AMV makes in-production module testing with Test Systems TSA and TSU faster and more versatile.

Photo 43 122/1


Test System TSU or two of the 23 slots inBoard Test System TSA. This compact-ness leaves space for switching panelsas well as driver/sensor modules. A32-bit DSP controls coordination andcommunication between all internalunits and evaluates test traces. Stimu-lation and recording can be run in parallel. Accuracy and clock rates areselected to comply with key productiontest requirements.

Fixture concepts and TSA/TSU system platforms remain compatible, so existing systems can be brought up to the latest status with an upgrade.Existing in-circuit tests are by and large compatible with the new versionsand benefit from the higher throughput.The new facilities of functional testing cover a wide range of applications.The technician is not compelled to opt for a test strategy when purchasingthe system. Such considerations can be left until programming, ie when detailed trimming instructions are available.

Standard instrument functionsIt is possible to set up any combinationof individual instruments. Up to five DCsignals of different power rating can be stimulated at the same time and sovoltages of up to ±100 V and currents

of up to 200 mA can be generated. DC voltages from 20 µV to 500 V andcurrents from 500 pA to 1 A can bemeasured. Two integrated amplifiers allow DC and AC signals to be boostedto ±100 V and grounded signals to be converted into floating ones. The 32 digital input and output ports afford simple control of the DUT.

In-circuit measurements are performedby virtual units, which in turn combineseveral units of AMV. Among the in-cir-cuit tests are resistance and impedancemeasurements, shorts, contact and continuity tests as well as IC check (node impedance method).

Waveform analysis and generation

A key unit for complex measurements isthe dual-channel waveform analyzer.It can measure voltage and current at a sampling rate of up to 10 MHz anddetermine the DC average, rms or peakvalues (up to 500 V and 1 A). Time-related test parameters are frequency,period, time interval, pulse width, dutycycle, rise and fall time. The numberand time of events (edges, relative maxima/minima) can be determinedfrom the traces or the traces can be compared with a tolerance mask (FIG 3). While conventional storage oscilloscopes were essentially devel-oped for interactive visual evaluation,the waveform analyzer of AMV is designed for automated, reproducibletests in production environments.Thanks to comprehensive triggering facilities, only those trace segments ofinterest are first saved in the 64-K mem-ory and then searched for the desiredcriteria. With preset evaluation triggerthresholds and hysteresis it is possible toclearly determine the actual event froma signal impaired by noise or interfer-ence without the risk of misinterpretingany fluctuation as a maximum (FIG 4).These evaluations are run at optimumspeed in the test unit under DSP control.Time-consuming downloading of tracesis thus done away with.

Articles

FIG 2 Analog MultifunctionModule AMV requires only twoslots in Test SystemsTSA and TSU to enhance functionalityconsiderably.Photo 43 122/2

FIG 3 Virtual instrument

panel of waveformanalyzer with

current settings can be called up in

debugger.


in single-shot mode with a clock rate ofup to 10 Msamples/s at an amplitudeand offset of max. 10 V (Vpp = 20 V).A floating high-voltage signal gen-erator with a peak-to-peak voltage ofup to 200 V, as required in the telecom-munications and automotive industry,can be generated by means of a high-voltage and isolation amplifier. Traceslearned by the analyzer can again bestimulated by the generator.

Switching panel and trigger systemThe individual units are integrated intothe switching panel and the triggersystem. They are connected to a 12-wirevideo bus that is routed direct to thetwelve video pins of the fixture interfaceand to the 6-wire analog bus and thusto maximally 1088 pins in Test SystemTSA. In a similar way five local andthree global trigger lines interconnectall internal units and so, for example,establish contact to the digital test unitand to external units (IEC or VXI). Thespecifications of the modules applythrough to the fixture interface includingthe switching panel, while with othermodule-oriented concepts the user is required to interconnect the modules

and establish connection to the DUT using relay modules and to evaluate the degraded system data. In AMVswitchable video pins, direct signal inputs and outputs as well as triggerpins are applied to the fixture interface,so minor measurement tasks can beperformed without the need for extratest or switching modules. This means avery low entry price for a one-modulesystem in conjunction with TSU.

Software

Part of the new measurement tech-nology is the new Test System SoftwareTSS 5.0, a 32-bit Windows NT appli-cation. Operation is in the customaryway as with other Windows-orientedapplications. Data exchange with otherNT applications is possible via clip-board or DDE. The combined editor/debugger simplifies and speeds up programming and debugging withouttime-consuming compilation. Switch-over between edit and execute is per-formed at a simple mouse click. Variousgraphical tools such as virtual panels,statistics and trace displays for resultsor symbolic breakpoint displays makefor transparent debugging. TSL (testsystem language) enhanced with theadditional functions of the new unitscontinues to be the programming language.

Outlook

Thanks to AMV measurement tech-nology, users of in-production testersTSA and TSU are excellently equippedfor all future measurement tasks. Time-critical measurement tasks can be im-plemented, if required, with customer-specific firmware. Due to the transpar-ency of the hardware, software and fixture concept, the long-time user of a Rohde & Schwarz test system cansimply modernize it without having to purchase a new, non-compatiblesystem.

Dr Lothar Tschimpke

REFERENCES

[1] Tschimpke, L.; Kundinger, K.: Universal TestSystem TSU – Versatile test platform for pro-duction and service of electronic modules.News from Rohde & Schwarz (1995) No. 150, pp 13–15

[2] Tschimpke, L.: LaserVision System LV1 – Op-tical insertion testing combined with classicboard test. News from Rohde & Schwarz(1995) No. 150, pp 10 –12

[3] Tschimpke, L.: Low-cost continuity check inboard testing using Cocheck II. News fromRohde & Schwarz (1997) No. 154, pp 24–25

Articles

The dual-channel arbitrary waveformgenerator of AMV generates periodicstandard curves and freely program-mable ones. One or more signals fromthe 64-K memory can be programmed

Realsignal

Idealsignal

Hysteresis

Forwardsearch

Backwardsearch

Duration of signal level drop

t1 t2

FIG 4 Measurement of duration of signal leveldrop between first falling below maximum level t1and reaching stable final value t2. Preset hyster-esis and forward/backward search allow realmaxima to be filtered out of noisy signals.

Condensed data of Multifunction Module AMV for TSA, TSUDC stimulation range ≤100 V, ≤200 mA

AC stimulation range ≤100 V, ≤2 MHz

DC measurement range 20 µV to 500 V, 500 pA to 1 A

AC measurement range 100 µV to 500 V, ≤2 MHz

Waveform generator (2 channels) sinewave, triangle, squarewave, arbitrary,1 channel floating, ≤200 V (Vpp)

Waveform analyzer (2 channels) voltage, current, frequency, time,1 channel floating, ≤500 V

Switching panel/trigger bus 12-wire analog bus/8 trigger lines

In-circuit tests R, L, C, Z, transistors, diodes, shorts, continuity, contact, IC check



The new DAB transmitters (FIG 1) are of modular design (FIG 2) and made up of the following components:• DAB exciter,• power amplifier,• power supply,• transmitter rack.

Band III transmitters are available with output power of 50 W to 2000 W(NA6... series), L band transmitters with output power of 50 W to 750 W(NL6... series). The entire DAB trans-mitter is controlled from a PC by meansof software running under Windows or via a display on the exciter.

The DAB exciter with integratedCOFDM modulator is able to processETI (ensemble transport interface) input signals of the type ETI(NI, G703)and ETI(NA, G704) to ETS 300 799.The output generated is a DAB signal to ETS 300 401 at the RF (FIG 3). Formonitoring purposes either the selectedinput signal can be output or the ETI(NI)

signal after NA decoding and delaycompensation. A FIFO in the inputstage buffers input signal timing fluctua-tions with respect to the reference clock.

The subsequent NA/NI converter auto-matically detects whether an ETI(NI) orETI(NA) signal is applied. An ETI(NA)signal requires deinterleaving andReed-Solomon decoding. The timestamps contained in the signal are eval-uated and used to control dynamic de-lay compensation (up to 1 s). The data

Articles

DAB Transmitters NA6… and NL6…

Digital audio broadcasting – reliable and economicalFollowing numerous international DAB pilot projects, the actual introduction ofdigital audio broadcasting is now beginning. This means that existing transmitternetworks will be expanded to provide full coverage. Rohde & Schwarz has developed new DAB transmitters for both VHF band III and L band that meet notonly present but also future requirements and offer high transmission quality andprofitability.

stream can additionally be delayed byup to 750 ms by a static delay section.The ETI signal transports data channels,which may be used for configuration (TII, static delay, etc) of the transmitternetwork, in both the NA layer (NASC: NA signalling channel) and NI layer (MNSC: multiplex network signalling channel). These data are

FIG 1 DAB Transmitters NA6... (band III) for125 W to 2 kW are accommodated in 19-inchracks of 2 m height. Photo 43 070

ETI signal

DAB exciter Divider

Power supply

Poweramplifier

Blower

Power supply

Poweramplifier

Coupler

Display

Bandpassfilter

Blower

FIG 2 Layout of 500 W

DAB transmitter (250 W redundant)


extracted from the data stream and taken to the controller for evaluation.The NA/NI converter then applies the delayed data stream to the nextfunctional unit: the first DSP. This DSPanalyzes the incoming signal, ob-taining configuration information and detecting dynamic reconfigurations. Ifthe error rate is too high in the check-sums for control data and information,the modulator output signal is switchedoff. Then follow convolutional codingand time interleaving. For test pur-poses a PRBS (pseudo-random binarysequence) can be inserted in a sub-channel.

The second DSP generates the transmis-sion frame according to the DAB modeselected as well as the DAB time signal.It also produces the desired TII patternin the null symbol and adds a guardinterval to the computed DAB symbols.The subsequent FIR filters limit the spec-trum and increase the sampling ratefrom 2.048 MHz to 32.768 MHz. Thedigital precorrector is able to correctthe current amplitude and phase of the signal and to influence the fre-quency response. The time signal canthus be tuned optimally to the poweramplifier characteristic. The signal isthen converted to band III frequency bydirect modulation (without IF). For out-put in L band the signal is upconvertedto L band frequency. The reference fre-quency is derived from the integratedGPS receiver or applied externally.

The power amplifiers are character-ized by high linearity and efficiency aswell as compact design. The band IIIamplifiers are built with MOSFETs,those for L band with bipolar transis-tors. These power transistors featurehigh peak-power margins, so powerpeaks caused in the DAB signalthrough the use of the multicarrier method and phase shift keying will not cause intermodulation products orincreased bit error rates of the DAB signal. A special feature is the circula-tor installed at the power amplifier output, preventing all kinds of slow or fast reflections that might destroy

the power transistors. New, patented power couplers minimize power loss inthe event of amplifier failure. With conventional couplers, transmitter out-put power is reduced by 6 dB for example if one of two amplifiers fails,but with the new couplers power reduc-tion is only 3.5 dB.

Each complete amplifier plug-in of thenew DAB transmitters has a separatepower supply, and each plug-in forms a self-contained mechanical unit.This concept automatically ensures redundancy for the supply voltages ofthe amplifiers. To keep cabling in thetransmitter rack to a minimum and toensure high operational reliability, thepower supplies are designed for onevoltage only. The amplifiers generateall the other voltages they require internally, which again makes for redundancy. The power supplies aredesigned as short-circuit-proof, primaryswitched-mode regulators for three-phase or optionally single-phase opera-tion depending on the total power

consumption of the transmitter. Due tothe high efficiency of more than 85%, a small built-in blower is sufficient toprovide proper cooling. The power supplies can be replaced without interrupting the running program by un-doing the plug-and-socket connection(provided that power supply and ampli-fier are redundant).

Transmitters with output power up-wards of 125 W (band III) or 100 W (L band) are accommodated in 19-inchracks 2000 mm high and only 800 mm deep. The output bandpass filter is integrated in the rack. For band III the transmitter and filter complywith the spectrum mask for critical areas. Where the amplifier and powersupply are redundant, the air coolingsystem is redundant too. This meansthat two blowers are integrated in the transmitter rack. Cooling air can be taken from and expelled to the trans-mitter room or taken and/or expelledexternally. Air intakes and outlets areprovided for this purpose at the top and

Articles

NA/NI decoder,synchronization,

delay compensation,MNSC/NASC

extraction

Ifs2 Qfs2

BufferError control,

time interleaving,PRBS insertion

RF 90°

AD

AD

DataClockSync

FS24 ms

HDB3 decoder,

input FIFO,input switch

ETI standby

ETI main

ETI

Generation of transmission

frame,DAB time signal,

TII pattern,guard interval

DSP2

I/Q datafs1

FIR filters

FIRFIR

Digitalprecorrector

LO1

Synthesizer

2.048/10 MHz

GPS1 PPS

GPS REF

2.048 ETI2.048 MHz

1 PPS

Band III

ControllerRS-232-C

RS485

Input stage NA/NI converter DSP1

GPS antenna

FIG 3 Block diagram of DAB exciter


The invention relates to and is based on a methodand equipment used to transmit digital sound signals from recording studios to the individual stations of a terrestrial broadcasting network. In future systems for digital audio broadcasting it will be necessary to transmit a large number ofprograms from the recording studios of the broad-casters to the stations of the terrestrial networks thatare planned nationwide.

It is the aim of the invention to create a simplemethod and equipment for the achievement of the above. This aim is established by a method according to the main claim. Further expedient developments according to this invention especial-ly as far as the equipment for applying this methodis concerned, namely in a DAB network, in a common terrestrial VHF FM transmitter networkand other extended DSR methods result from thesubclaims.

The assumption is made that the DS1/DSR methodknown for the supply of consumer broadcast receivers via a satellite transmitter is best suited for sending sound signals from a recording studioto the individual stations of a broadcasting net-work. A DS1/DSR method of this kind only allowstransmission of 16 individual programs however,since the familiar DSR coder only offers 16 DS1channels. As future broadcasting networks willhave to send considerably more programs to theindividual transmitter stations at the same time, theinvention provides for additional data reduction ofthe sound signals to be transmitted in the recordingstudio in combination with this DS1/DSR methodand by taking psycho-acoustic phenomena of thehuman ear into account. The MUSICAM method

(masking pattern adapted universal subband integrated coding and multiplexing) for example issuitable for this. It is used to transmit sound signalson narrowband channels like telephone linesbetween recording studios and transmitters. Combination of a DS1/DSR satellite transmissionmethod with such a familiar means of data reduc-tion allows transmission of not just 16 programs to the individual stations of a DAB network, for instance, but even a multiple of this figure. Themethod according to the invention is highly eco-nomical too, since it can be implemented usingcommercial equipment. The method is also verysuitable for supplying the individual stations of a DAB network since, depending on the degree of data reduction, three to seven times as manyprograms can be transmitted as with DS1/DSR,which is limited to one stereo program (or twomono programs) per DS1 channel and to 16 stereo programs per DSR channel.

Likewise, the method according to the invention isalso suitable to supply a common terrestrial VHF FMtransmitter network or a so-called compatible DABnetwork in which only one digital program signal is emitted per transmitter in the frequency band normally used for a VHF FM transmitter.

For the method according to the invention a common satellite transmission system is preferredas the broadband transmission system, but transmission can also be via a broadband cablenetwork.

The method can also be used to extend the well-known digital sound-broadcasting systemDSR (extended DSR, EDSR) by simply equipping

the consumer receiver required for DSR satellite reception with a corresponding MUSICAM de-coder chip comprising selection logic. The user of such a receiver can select the required data-reduced sound signals from the digital sound signals transmitted with the method according tothe invention and listen to them. The known DSRtransmission system can thus be expanded to amultiple of the programs offered up to now.

Articles

bottom of the rack. The 50 W trans-mitters for band III and L band are accommodated in 19-inch racks 1000 mm high and 600 mm deep.

Rainer Steen; Cornelius Heinemann;Peter H. Frank

Condensed data of DAB Transmitters NA6…/NL6…Frequency range 174 MHz to 240 MHz (band III)

1.452 MHz to 1.492 MHz (L band)

DAB modes I, II, III, IV

Output power 50 W to 2000 W (band III)50 W to 750 W (L band)

Input signal ETI(NI) or ETI(NA)

Standard ETS 300 401

Power supply 3 x 400 V ±10%


PatentMethod and equipment for transmission of digital sound signals in terrestrial broadcasting networks

Extract from patent specification EP 0 510 247 B1

Patent applied for by Rohde & Schwarz on 02 August 1991

Issue of patent published on 12 June 1996

Inventor: Paul Dambacher

Used with DSR Modulator SFP (photo), AudioCoder DCA, Digital Sound Receiver DSRE, Digital Sound Converter DSRU, MUSICAM Codec MUSIC

Reader service card 158/05 for further information on units mentioned


The wide range of applications of Vehicle Location System VELOS (FIG 1)covers use by security transporters, police, fire brigades and local publictransport enterprises, ground taxiing location at airports, vehicle location on factory premises or determination of ships’ positions in ports. Thanks tothe high location speed and the use of

DGPS (differential GPS) the user canobtain accurate and current positiondata of his vehicles at any time, whichis especially important in security-related operations.

The nucleus of the control center and also the mobile stations is a fast radio data module. Depending on the

required accuracy of the position data,the location system can be supplied inthe following two versions:• without correction of position data

(inaccuracy <100 m),• with correction of position data by

DGPS according to RTCM104 standard (Radio Technical Commit-tee for Marine Services) with maxi-mum inaccuracy of only 5 m.

The control center comprises a locationcontroller with system software as well as a GPS reference station with integrated radio data module. The GPSreceiver generates the RTCM correctionsignals. Transmission of these signalsand data exchange with the mobile stations is effected via the radio datamodule. To increase system availability,the reference station can be imple-mented in a redundant configuration,ie master reference station and standbyreference station each with their own location controller (FIG 2). The two controllers are interconnected either viaan RS-232-C interface (in case of longdistances via modem) or by an LAN.When the controller systems are con-figured as a server, the location resultsare made available to the customer’snetwork or the particular application(eg via Ethernet with TCP/IP protocol).The radio network can be configuredvia the network interface, in particularthe logging on and off of participatingmobile stations. To calculate the posi-tion correction in a DGPS system, the GPS antenna positions of the tworeference stations must be accuratelydetermined in WGS84 coordinates (World Geodetic System 1984), whilein a standard system without positiondata correction the GPS receiver is notrequired.

The main components of each mobilestation are a GPS receiver and a radiodata module for connection to the radiolink (FIG 3). The GPS receiver of eachmobile station outputs position dataonce per second via a serial interface(RS-232-C), which are however onlytransmitted to the control center if requested by the location controller.

Articles

Vehicle Location System VELOS

DGPS-supported vehicle locationwith fast radio dataVehicle Location System VELOS is used to determine the position data of mobileobjects and to transmit these data to a control center where the data are storedand displayed on a map and other user-defined tasks are performed. Data transmission is via a radio network that allows up to ten vehicles to be located persecond. Alternatively, data can be transferred via a customer’s own radio datanetwork or GSM.

FIG 1 Components of Vehicle Location System VELOS: reference station,controller and mobile station (compact and 1/2 19-inch design)Photo 43 112


For this purpose the location controllercyclically polls the position data of themobile stations via radio, ie a TDMA (time division multiple access) methoddirected by the controller is employed.The transmission of RTCM correctiondata is also integrated into the TDMAstructure, meaning that only one radiofrequency is required for the trans-mission of correction data as well asposition data.

The high data rate of the radio datamodule (9.6 kbaud) allows the positiondata of up to ten vehicles to be trans-mitted per second. The position data ofmobile stations polled by the locationcontroller can be stored in a databaseand displayed on a digital map. In the case of large fleets, vehicles are displayed by priority: vehicles with certain addresses or status messagescan be displayed continuously, whilethe other vehicles are selected from the database for display. User-specificmodifications or extensions of thesystem software allow transmission ofadditional, short user-defined messagesfrom the mobile stations (eg alarms, other status messages), and positiondata transmission by a mobile stationcan be triggered manually by an emergency key for instance. The de-tection of alarms and other messagesas well as the emergency key can be implemented on analog and digital inputs of the mobile station. Reduced location speed then has to be expected because the data messagesare longer.

To maintain location during short interruptions of the GPS satellite signalcaused by shadow effects, a dead-reckoning sensor system is availablefor the mobile stations. This system consists of two acceleration sensorsmounted perpendicular to each other

In Germany RTCM correction data are provided by the satellite positioningservice SAPOS within the realtime posi-tioning service EPS. SAPOS is formedby the association of the survey officesof the different federal German states.The correction data are sent via VHF-RDS in cooperation with ARDbroadcasters, on longwave with German Telekom, and in the 2 m bandvia geodetic surveying transmitters. Use of these correction data requires a special data receiver with decoder,operated instead of the GPS receiver inthe VELOS control center. RTCM dataoutput by the receiver can be trans-mitted to the mobile stations via radiodata integrated in the system. This solution saves the user installation of the GPS reference receiver and deter-mination of the reference point.

Dr Rolf Springer; Dr Lothar Schirm

Articles

along the vehicle axis as well as a gyrosensor. The sensors can be installedwith minimum effort and do not requireany modifications to the vehicle, aswith wheel-mounted speed sensors for example.

Condensed data of Vehicle Location System VELOSGPS reference receiver 12-channel receiver, C/A code, frequency band L1,

correction data generation to RTCM SC-104

Mobile GPS receiver 6-channel or 12-channel receiver, C/A code, frequency band L1, RTCM-compatible

Radio data moduleFrequency/transmitter power 170 MHz/0.5 W (in line with FTZ 17 TR 2014),

other frequency bands on requestChannel bandwidth 20 kHzModulation type GMSKData rate (air interface) 9.6 kbit/sTX/RX switchover <50 ms


2 x RS-232-C

Telemetrytransceiver

DGPSreceiver

220 V

Master reference station

Telemetrytransceiver

DGPSreceiver

220 V

Standby reference station

2 x RS-232-C

RS-232-C,modemor LAN

Alarms,additionalinformation

Dead-reckoning system (b, α, ϕ)RS-232-C 10 V to 36 V

Telemetry transceiver

GPSreceiver

Mobile station

FIG 2 Layout of control center (redundantconfiguration)

FIG 3 VELOS mobile station (options in blue)


Monitoring terrestrial emissions andsignals from geostationary satellitescalls for different antenna concepts interms of gain, polarization and posi-tioning accuracy. Antenna SystemsAC090 to AC300 (FIG 1) meet theserequirements, offering four different reflector sizes with corresponding gain(FIG 2) and matching rotators as well

as a variety of feeds with and withoutpreamplifiers.

Frequency ranges 1 to 18 GHz for linear and circular polarization and 1 to 26.5 GHz for linear polarizationare covered by broadband feeds [1].Low-noise preamplifiers integrated inthe feed boost the detected signal,which is routed to the antenna feed-point via low-loss cables for further processing. Frequency ranges 18 to26.5 GHz and 26.5 to 40 GHz arehandled by two add-on antennas

flanged to the side of the main reflectorfor mechanically selectable linear pola-rization. Advances in amplifier tech-nology and spectrum analysis towardsincreasingly higher frequencies [2] nowallow direct preamplification and signal processing. If signal conditioningis limited at 18 GHz, optional down-converters are available for convertingfrequencies between 18 and 40 GHzto the range below 18 GHz. Anotheroption available for Microwave Anten-na AC300 is a frequency extension inthe form of two logarithmic-periodic an-tennas for horizontal and vertical pola-rization in the range 80 to 1000 MHz.

The antenna systems can be positionedsimultaneously in azimuth by ±180° atabout 5° per second and in elevationfrom –5° to +95° at about 2° per second. Rotator control as well as selection of antenna and polarizationare effected from a computer runningunder Windows NT 4.0 (FIG 3), whichmay be set up at a distance of up to 1 km. So cabling routed to the antennasystems is restricted to power supply,signal conditioning and a two-wirecomputer link.

Design

Antenna Systems AC090 to AC300comprise the following elements:• main reflector (90, 120, 180 or

300 cm),• rotator,• control unit for positioning and

selecting antenna and polarization,• supporting structure,• set of cables,• feed 1 to 18 (26.5) GHz,• add-on antennas 18 to 26.5 GHz

and 26.5 to 40 GHz.

The antenna systems are designed sothat they can be retrofitted and feedscan be replaced without any modifica-tion to the system, for example to matchthe system to new monitoring tasks.Whatever the application, it is only necessary to modify the initializationand control software that comes withControl Unit GX300.

Articles

Antenna Systems AC090, AC120, AC180, AC300

Radiomonitoring in microwaverange up to 40 GHzRohde & Schwarz has developed steerable Antenna Systems AC090, AC120,AC180 and AC300 with parabolic reflectors of 90 cm to 3 m in diameter for radiomonitoring applications in the frequency range 1 GHz to 40 GHz. In additionto selectable reflector diameter, a large variety of feeds with different polariza-tion, frequency ranges and preamplification are available for numerous missions.

FIG 1 Microwave Antenna System AC090 withadd-on Antennas AC308 Photo 40 577/2


Feeds and add-on antennas

Feeds include logarithmic-periodicbroadband antennas in planar configu-ration for linear polarization with ap-proximately identical radiation patternsin azimuth and elevation. The broad-

band antennas are also available in a crossed configuration for linear andcircular polarization (FIGs 4 and 5).

Use of broadband feeds above 18 GHzis expedient mainly for monitoring taskswith a maximum reflector diameter up

to 120 cm, since the half-power beam-width of the radiation patterns may become too small with larger reflectors.To accommodate for larger diameters,Antenna AC308R2 for the frequencyrange 18 to 26.5 GHz is additionallyavailable. An overview of availablefeeds and add-on antennas is given inthe blue BOX.

Control

After installation, which can be carriedout by the customer himself, the an-tenna system is initialized by means of the software supplied with ControlUnit GX300. Following selection of thebasic configuration (eg AC120), the

Articles

50

45

40

35

30

25

20

15

10

dB

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 GHz

f

AC090AC120AC180AC300

FIG 2 Gain of microwaveantennas with Feed HL024A1

FIG 3 User interface (Windows NT) forAntenna AC120

Feed Frequency PolarizationHL024A1 Crossed log-periodic antenna 1 to 18 GHz H or VHL024S2 HL024A1 with passive polarization network 1 to 18 GHz H or VHL025 Log-periodic antenna 1 to 26.5 GHz linearHL025S Rotatable HL025 with preamplifier 1 to 26.5 GHz adjustableHL024S5 HL024A1 with narrowband preamplifiers 2 to 18 GHz H or V

2 to 4 / 4 to 8 / 8 to 12 / 12 to 18 GHzHL024S7 HL024A1 with preamplifier 1 to 18 GHz H or VHL025S7 HL025 with preamplifier 1 to 26.5 GHz linearHL024S8 HL024A1 with two preamplifiers 1 to 18 GHz H and VHL024S9 HL024A1 with active polarization network 1 to 18 GHz H, V, RHC or LHC

Add-on antennasAC308R2 250 mm reflector antenna, 29 to 33 dBi 18 to 26.5 GHz H, V or 45°AC308R3 250 mm reflector antenna, 33 to 36 dBi 26.5 to 40 GHz H, V or 45°AC300A4 Log-periodic Antennas HL023 0.08 to 1.3 GHz H and V

FIG 5 Feed HL024S5 (2 to 18 GHz) for linearand circular polarization

Photo 43 031/1

FIG 4 Feed HL025 (1 to 26.5 GHz) for linearpolarization Photo 33 011


The EMC Asia symposium, held in Singapore forthe first time last autumn and intended for all Asiancountries, met with a very positive response. Thesymposium was combined with workshops and anexhibition. Like European EMC events of this kind,the symposium was organized by Germany’s MESAGO Messe und Kongress corporation, which recorded 812 participants for more than430 workshops and almost 50 exhibitors present-ing their products in an area of about 1000 sqm.“Testing the Limits” was the motto of Rohde &Schwarz (FIG), whose product presentation focused around EMI Test Receivers ESCS30 from 9 kHz to 2.75 GHz and ESPC for 9 kHz to 2.5 GHztogether with EMC Test Cell S-LINE. The stand wasmanned for the most part by specialists from theRohde & Schwarz Support Centre Asia (SCA),newly set up in Singapore just a few weeks before.Although the majority of visitors came from Singa-pore, contacts to Korean, Taiwanese and Thai customers were established as well. SCA offerssystem solutions, calibration and service for allAsian countries, so travel and time will be reducedsubstantially for customers in the region.

The lectures and discussions held in the WestinStamford & Westin Plaza Convention Centreunderlined that electromagnetic compatibility isbecoming more and more important for com-

panies in Asia and will remain so in the future.With increasing globalization of markets, thesecompanies are facing demanding internationalchallenges and cannot only keep up with Euro-pean manufacturers of electronic products but

even have an edge in some market segments. As a consequence of the success of the first-time event,it was decided to stage it annually in future.

Volker Janssen

Articles

feed used and any add-on antennasand alignment to north, the system isready for operation. The rotator can be controlled manually or moved topreselected or stored positions.

Klaus Friede; Ludwig Nielsen

REFERENCES

[1] Schiller, M.; Linhuber, E.: Logarithmic-periodic antenna for 1 to 15 GHz. News from Rohde & Schwarz (1971) No. 49, pp 22–24

[2] Evers, C.: 100 Hz to 26.5 GHz – new levelof performance for microwave region withSpectrum Analyzer FSM. News from Rohde& Schwarz (1991) No. 133, pp 4–7

Condensed data of Microwave AntennasAC090 AC120 AC180 AC300

Reflector 1 [ 0.9 m [1.2 m [ 1.8 m [ 3 mFrequency range 1 to 18 GHzGain 15 to 40 dB 19 to 42 dB 23 to 45 dB 26 to 50 dBHalf-power beamwidth 19° to 1.3° 16° to 0.9° 12° to 0.7° 6° to 0.35°

Reflector 2 [ 0.25 m (AC308R2)Frequency range 18 to 26.5 GHzGain 29 to 33 dBHalf-power beamwidth 4.5° to 3°

Reflector 3 [ 0.25m (AC308R3)Frequency range 26.5 to 40 GHzGain 33 to 36 dBHalf-power beamwidth 3° to 2°

Beamwidth rotatorRange of rotation azimuth ±180°; elevation –5° to +95°Speed azimuth >3°/s; elevation >2°/s

Inaccuracy <±0.2° <±0.2° <±0.2° <±0.1°


In brief EMC Asia 97 – debut in Singapore

Phot

o: a

utho

r


Wireless communication is making in-creasing use of broadband techniquesor time compression. Monitoring thesesignals calls for systems capable of simultaneous detection and directionfinding of all emissions across a widefrequency range. Among the digital direction finders of the DDF series [1; 2], the new Scanning DirectionFinders DDF0xS feature the highestscanning speeds irrespective of radiospectrum occupancy.

Design and function

Digital Scanning Direction FinderDDF0xS (FIG 1) features excellent characteristics thanks to digital signalprocessing throughout. The IF signalsof the triple DF converter are digitizedand distributed to parallel frequencychannels. Bearings are calculated simultaneously with filtering so that the direction of incidence is obtainedquasi-parallel for all channels within the bandwidth analyzed.

Each DDF0xS is basically made up of HF DF Converter EH091, which in-cludes three DF receiver modules andan A/D converter, and Digital Pro-cessing Unit EBD92D (FIG 2). In theVHF-UHF bands, VHF-UHF ConverterESMA33 is connected ahead of the direction finder in addition. The direc-tion finders for the HF band (0.5 to 30 MHz) are designated DDF01S,those for HF plus the VHF-UHF bands(0.5 to 30, 30 to 650/1300 MHz) arenamed DDF06S.

The direction finders of the DDF0xSgroup have the algorithms for the Watson-Watt method and the prin-ciple of correlative interferometer implemented as standard. The Watson-Watt method is used where maximumscanning speeds are to be achievedand/or space is at a premium for DF antennas in the HF band. If, on theother hand, extremely high accuracy is required at unfavourably located an-tenna sites or the elevation of incomingsignals is to be determined additionallyin the HF band, the correlation methodis the better choice.

The digital filter bank of DDF0xS allowssimultaneous signal processing acrossa frequency band of 200 kHz. Thisbandwidth offers maximum dynamicrange. Nonlinear distortion products at the output of the A/D converter areminimized by highly effective prese-lection filters (excellent large-signal behaviour) and by gain adjustment performed prior to each scanning cycle.For scanning larger frequency ranges,

the 200 kHz window is rapidly in-cremented and fresh A/D conversion ofthe analog signal is performed (scanmode). DDF0xS requires approx. 3 msto change frequency in the HF bandand approx. 0.9 ms in the VHF-UHFbands; the time required for gain control of the analog receiver section isincluded in these figures.

Articles

Digital Scanning Direction Finders DDF0xS

Fast direction finding of broadband and short-term signalsDigital Scanning Direction Finders DDF0xS are designed for extremely highsearch rates, making them ideal for interception and direction finding of broad-band and short-term signals in the frequency range 0.5 to 1300 MHz. Multileveldata compression makes it possible to use these direction finders as automaticsearch tools in complex radiomonitoring and radiolocation systems.

FIG 2 Block diagram of Digital Scanning Direction Finder DDF0xS

FIG 1 Digital Scanning Direction Finder DDF0xSPhoto 43 123

VHF-UHFantennas

HF DF ConverterEH091

Digital Processing UnitEBD92D

Ant

enna

sel

ecto

r

VHF-UHF tuners

HFantenna

A/D

con

verte

r

HF tuners

Controller

Optional bearingcorrection

Signal processor

OptionalGPS receiver

Data

Control

VHF-UHF DF ConverterESMA33

IF=21.4 MHz Digital IF


bandwidths result in effective adjacent-channel rejection and high scanningspeeds at the same time (FIG 3).

Operation and recording of resultsAn external controller incorporating theDF-specific control and display toolsserves for operation of the directionfinder and display of results (FIG 4).The well-devised operating concept isbased on extensive testing and opera-tional experience:• The measurement windows occupy

the largest area.• Only those control elements that are

constantly needed are permanentlydisplayed.

• The user interface allows strain-freeoperation over an extended periodof time.

• All important operational data aredisplayed within an easy viewingangle to prevent operator fatigue.

• Measurement windows can be ar-ranged on the display as desired,and the configuration can be savedand recalled at a mouse click.

• Special tools provide semi-automatichelp for fast detection, direction finding and analysis of agile signals(hoppers, bursts).

• Various options are available fordata recording and evaluation.

• A variety of measurement windowscan be chosen for results display:level vs time, azimuth vs time, azimuth vs frequency, level vs frequency, elevation vs frequency,azimuth histogram, level histogram,elevation histogram, alphanumericdisplay of DF results.

The direction finder offers the followingfunctions for the documentation andanalysis of detected signals: • For short-term recording, all DF data

collected during the past minute are saved at a keystroke to harddiskor a virtual drive.

• For long-term recording, DF data are permanently stored to harddiskor a virtual drive.

• Data analysis can be performedwhile recording is in progress usingthe scan replay or activity analyzerfunction.

• The volume of data saved dependssolely on harddisk capacity. Thedata rate is 2 to 15 Mbytes per minute depending on the filter used.

For users who want to analyze signalcontents with their own tools, the activity analyzer provides an exportfunction that converts data to ASCII format (eg for Excel).

Probability of intercept

The most important function of DDF0xSdirection finders is interception of frequency-agile and burst signals. Thesuitability of emissions for interceptionand direction finding is judged by probability of intercept (POI). Reliablebearings of frequency hoppers, and inparticular with low S/N ratios, are notpossible until the emission has beenintercepted a number of times. So it is best to consider the probability of a signal being intercepted at least n times. The signal of the frequencyhopper is characterized by its dwelltime, the frequency band covered and channel spacing. The example inFIG 5 shows the probability of inter-cepting a signal from a VHF or UHF frequency hopper at least ten times as a function of the time during which it is emitted. It can be seen that a signal of 300 hops per second will

Articles

Proper balance of preselection andgain is a basic requirement for optimumreception and direction finding, whilethe design of the digital filter bank determines the spectral selectivity of the direction finder. The skirt selectivityof filters and thus the achievable spec-tral selectivity are inversely proportion-al to the length of the analyzed signalsegment. So a compromise had to befound to save the ope2ator from havingto adapt the window to the task in handeach time, but enabling fast scanningof short-term signals also in densely oc-cupied bands. The use of a windowingtechnique, pre-averaging of scanningvalues and the selection of suitable

Rectangle

Flat topHann

FIG 3 Selectivity of various windowing functions

FIG 4 User interface with typical scenario of

broadband emitters in HF band. Waterfall

display (top) revealsfrequency-agile

emitters; histogram(bottom right) allows

unambiguous iden-tification of weak

frequency-hopped signals from over-lapping frequency

bands of same azimuth sector.


be intercepted after only 3.5 s with a probability of 85%, whereas approx.4.3 s are required for a signal of 3000 hops per second.

Antennas

Two types of DF antenna are availablefor the DF methods implemented inDDF0xS:• Antennas ADD012, ADD115 and

ADD155 have monopulse capabil-ity and are designed for maximumDF speed. Together they cover therange 0.5 to 650 MHz (Watson-Watt method).

• Interferometer DF Antennas ADD010,ADD011, ADD050, ADD150 andADD051 are especially character-ized by large bandwidth (only twoantennas are required for 0.5 to1300 MHz), high bearing accuracyand immunity to multipath propaga-tion. In the HF band these antennasallow determination of the elevationangle of skywaves and thus positionfinding by means of the single-station location manager.

The direction finder can of course be operated on existing antennas if these are suitable for the Watson-Watt method. Adaptation is made by Antenna Interface GX060 (0.3 to650 MHz).

Bearing correction and synchronization

To ensure highly precise bearings in environments with very strong inter-ference, eg onboard vehicles, ships or aircraft, a bearing correction option(EBD92AK) is available for DDF0xS. It allows continuous correction of bearings in the frequency range 0.5 to 1300 MHz over an azimuth range of 360°. Rohde & Schwarz offers soft-ware and services for a large degree ofautomation in the collection and pro-cessing of correction data. The bearingcorrection option improves the RMS deviation of bearings in frequency andazimuth by a factor of three to four.

Position finding – especially of fre-quency-agile signals – places the mostexacting demands on the synchron-ization of direction finders in a radio-location system during the scanningprocess. For this purpose direction finders can be equipped with a GPS receiver (option EBD92GP), which supplies a highly precise sync pulseand the time stamp (1 µs resolution) required for position finding.

Use in systems

In addition to its scanning qualities, Direction Finder DDF0xS offers all theattributes of an excellent monitoring

direction finder, which justifies its use as a stand-alone unit meeting the most stringent requirements. DDF0xS is especially suitable for integration intoradiomonitoring systems incorporatingintercept receivers, analyzers and dataacquisition terminals. In a radiomonitor-ing system the DF component essen-tially serves for direction finding, assignment of occupancy data to theiremitters and for determining the posi-tion of these emitters. Rohde & Schwarzhas developed the ScanLoc system forlocating frequency-agile emitters [3].This system allows a precisely syn-chronized scan of up to six DF stationsas well as realtime display of detectedemissions on digitized maps.

Franz Demmel; Wilhelm Genal; Ulrich Unselt

REFERENCES

[1] Demmel, F.; Unselt, U.; Schmengler, E.: Digi-tal Monitoring Direction Finders DDF0xM –State-of-the-art monitoring direction findingfrom HF to UHF. News from Rohde &Schwarz (1996) No. 150, pp 22–25

[2] Demmel, F.; Wille, R.: VHF-UHF DirectionFinder DDF190 – Digital direction findingfrom 20 to 3000 MHz to ITU guidelines.News from Rohde & Schwarz (1996) No. 152, pp 30–32

[3] Demmel, F.; Hinkers, G.: Networking digitaldirection finders for improving radiomonitor-ing efficiency and locating frequency-agileemitters. News from Rohde & Schwarz(1997) No. 156, pp 24–25

Articles

Condensed data of Digital Scanning Direction Finders DDF0xSHF band VHF-UHF band

Frequency range 0.3 to 30 MHz 20 to 650 (1300 MHz)

DF method correlative interferometer, Watson-Watt

DF error 1° RMS with ADD011 1° RMS with ADD051

Sensitivity typ. <1 µV/m with ADD011 typ. <2 µV/m with ADD051

Realtime bandwidth 200 kHz 200 kHz

Scanning speed 22 MHz/s 200 MHz/s (2 kHz bandwidth) (8 kHz bandwidth)

Minimum signal duration 4 ms 100 µs

Bandwidths 0.125 to 2 kHz in 5 steps 2 to 32 kHz in 4 steps

Displays bearings and levels vs frequencyhistogram of bearings bearings and levels vs time (waterfall)


1 2 3 4 5 6 7 8 9 s100

Transmit time

1

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

Prob

abili

ty

FIG 5 Probability of intercept of at least ten emissions of VHF frequency hopper (blue:300 hops/s, red: 3000 hops/s) with Watson-Watt method; scanning range of DDF0xS 50 MHz, hopping span of emitter 30 MHz, channel spacing 25 kHz


The number of electronic devices in auto-mobiles has increased dramatically inrecent years. They have made inroadsinto virtually all parts of the automobileand are no longer limited to top-of-the-range models as used to be the case.Today electronic fuel injection, airbagand ABS are the standard minimumeven in a small car. Considering thatsome 12 million vehicles are manu-factured annually in Western Europe,with about a third coming from Ger-man plants, automotive electronic modules generally rank as typical mass products. But in contrast to othermass products, very high requirementsare made where functional reliabilityand quality are concerned. This callsfor comprehensive quality assurance inproduction besides all the necessarymeasures in design and development.

The German company Kiekert, an auto-motive electronics supplier, specializesin locking systems and is a market leader in the field, delivering to variouscar manufacturers. The remote-controllocking systems, consisting of a trans-mitter and receiver, are manufacturedon several automatic production linesat the company’s plant in Düsseldorf.The signals from the remote-control unit to the receiver of the central doorlocking system used to be transmittedby infrared. A new production line was recently set up for units using high

frequencies to transmit the signals. Theelectronic modules are designed in sur-face-mount technology and producedfrom panel boards. The small sizemeans that the transmitter can be integrated into the car key.

To ensure high product quality, Kiekertchose a multistage test strategy, despitethe enormous cost pressures on sup-pliers to the automobile industry (FIG 1). Following component insertionand soldering, modules are checkedfor manufacturing defects and then

Application notes

Production test of RF modules with Universal Test System TSU, Radiocommunication Service Tester CMSand EMC test cell

FIG 1 Multistage test strategy for receiver module

FIG 2 RadiocommunicationService MonitorCMS54 (bottom left)together with Univer-sal Test System TSUused for functionaltesting of receivers(in EMC Test Cell S-LINE 700/P)Photo 43 027/2

Check for manu-facturing defects

Digitalfunctional test RF functional test


undergo a functional test. Defectivemodules are routed to a repair station,where they are corrected and then fed back into the production process.Rohde & Schwarz was responsible for the implementation of all functionaltesters, repair stations and the integra-tion of these systems into the automaticproduction line.

Functional test of transmittersand receivers of remote-control locking systems The functional test of the receiver circuitis divided into two separate tests: thedigital functional test and the RF test.During the digital functional test, all inputs and outputs at the connector arechecked. The tester also downloadsdata to the DUT’s memory via its inter-face. The test system consists of Univer-sal Test Station TSU [1] with digital testchannels and a power supply for theDUT. A second test system comprisingRadiocommunication Service MonitorCMS54 [2] performs the subsequent RFfunctional test, for which the DUT isplaced in a shielded test cell (FIG 2).CMS54 tests the response and sensi-tivity of the receiver.

The transmitter in the key is only sub-jected to an RF functional test and a LED check. Again the measurementsare performed in a shielded test cell.The measurements are all made withinthe cycle time of the production line.

RF measurements in EMC Test Cell S-LINE 700/PAccurate and reproducible measurementof transmit and receive parameters is avery important requirement. To excludeinterference from other transmitters, the receiver measurement has to be performed in a shielded environment.A conventional in-line fixture stationcould be modified so that external RFI is sufficiently damped, but the electromagnetic field within the shielded enclosure would not be homogeneous due to reflections fromthe installations and walls. So accurate

and reproducible measurements wouldhardly be possible. Rohde & Schwarzsolved the shielding problem with its S-LINE 700/P (a version of EMC TestCell S-LINE 700 for use in electronicsproduction [3]). Reproducibility of ±1 dB can thus be achieved in the frequency range 150 kHz to 1 GHz. To enable automated feed and interfacing of the DUTs, the modules are conveyed into the test cell through a bulkhead that opens and closes automatically.

Defective modules are taken to a repairstation equipped with a Universal TestSystem TSU and a spectrum analyzer (FIG 3). This station provides all the facilities required to test transmitter and receiver modules. No parametricmeasurements are performed here, soa test cell is unnecessary. All functionaltest systems are linked to Kiekert’s quality management system. This meansthat all data and results generated during tests can be called up at the station to support repairs.

Ideal partnership

Rohde & Schwarz’s wealth of expe-rience and competence in productiontesting and RF measurements was thedecisive factor in Kiekert’s choice of the company as its partner for this application. It was possible to imple-ment the project almost entirely with standard components from theRohde & Schwarz product range. Incontrast to an individualized solution,the required customer-specific adap-tations were therefore reduced to a minimum, so the customer benefitedfrom faster delivery, lower costs andbetter maintenance.

Klaus Kundinger

REFERENCES

[1] Tschimpke, L.; Kundinger, K.: Universal TestSystem TSU – Versatile test platform for pro-duction and service of electronic modules.News from Rohde & Schwarz (1996) No. 150, pp 13–15

[2] Hausdorf, R.: Mobile transceiver measure-ments with Radiocommunication ServiceMonitor CMS. News from Rohde & Schwarz(1989) No. 127, pp 4–7

[3] Göpel, K.-D.: EMC Test Cell S-LINE – Com-pact EMC test cell of high field homogeneityand wide frequency range. News from Rohde & Schwarz (1996) No. 151, pp 7–9


Application notes

FIG 3 Repair station for receivers based on Universal Test System TSU Photo 43 124


Modern communication systems forspeech and data – mobile radio, cordless telephones and pagers – trans-mit information by means of digitalmodulation. This means that all the information is modulated onto the transmit signal in the form of bits. Thequality of the receiver in the trans-ceivers used for this purpose is judgedby measuring bit error rate at low receive levels. For this purpose a link is set up to the mobile radio (or basestation) and a known data sequence istransmitted. The transceiver then sendsthe data back to the measuring instru-ment in loopback mode. The incomingdata sequence is analyzed and com-pared with the sequence originallysent. Since transmission from the mobilephone to the instrument is normally errorfree, any differences between the received sequence and the sent sequence are a measure of the qualityof the receiver used in the mobile radio.The errored bits are counted and referred to the total number of sent bits to yield the bit error rate (BER). Digital Radiocommunication TesterCMD or CRTP/CRTC performs theseBER measurements with ease at a keystroke [1].

Shadow effects, reflections and themovement of the receiver itself – beinga mobile radio – result in varying degrees of distortion of the receive signal (multipath propagation, multi-path fading [2]). Especially at fast datarates like in GSM (277.833 kbit/s) orCDMA (1.288 Mchips/s), the differentdelays of the signals cause bits sent earlier or later to arrive at the receiversimultaneously. This leads to serious demodulation problems, causing asharp increase in BER.

Various measures are implemented inreceivers to improve quality under fad-ing conditions. In GSM for example,the distorted receive signal is corrected by means of the midamble. The mid-amble is a known data sequence in thetransmit signal which always remainsthe same irrespective of the useful data but is of course subject to the samedegradation as the useful data duringtransmission. Any distortions of the midamble are detected by an equalizercircuit in the receiver. This informationallows correction of the useful data sentimmediately ahead of and after themidamble and thus marked improve-ment of BER. Mobile radios usingCDMA incorporate so-called rake re-ceivers. A rake receiver operates likeseveral receivers in parallel to analyzethe receive signal with different delays.The resultant signals are then combinedto produce an overall signal with theleast possible error.

Of course it is necessary to test whetherthese measures really do improve re-ceiver quality as intended. The variouscommunication system standards speci-fy BER measurements under conditionsof fading. Combining Radiocommu-nication Tester CMD, CRTC or CRTPand Signal Generator SMIQ fitted with the fading simulator option [2] produces an ideal test system for thepurpose (FIG 1). The radiocommuni-cation tester sets up the connection tothe mobile radio under test and carriesout the BER measurement. But the transmit signal, which normally comesfrom the radiocommunication tester for this measurement, is supplied here bySMIQ. The SMIQ signal includes thestipulated fading profiles, allowing BERmeasurement under fading conditions.

Pager signals and signals with analogmodulation (AM or FM) are of coursealso subject to the distortion caused ina fading channel. Such signals can begenerated by a combination of SignalGenerator SME or SMT and SMIQ

Application notes

Applications in and around fading

FIG 1Digital Radiocommu-nication Tester CMDand Signal Genera-tor SMIQ with fadingsimulator – an idealteam for measure-ments on mobile radios under fadingconditionsPhoto 43 110

FIG 2 Fading of pager signals and signals with analog modulation with Signal GeneratorsSME and SMIQ

ROHDE & SCHWARZ

SME

ROHDE & SCHWARZ

SMIQ

90°

RF1 +fading


(FIG 2). Rohde & Schwarz has pub-lished a number of application notesdealing with measurements under fading conditions (see list in blue BOX).They describe the test setups and instrument settings required for suchmeasurements. For example, Appli-cation Note 1MA02_0E outlines

measurements on GSM mobile radiosusing Digital Radiocommunication TestSets CRTP and CRTC in conjunctionwith SMIQ. Combinations of the widely used Radiocommunication Tester CMD in its various versions (CMD 55/57/65/80) and SignalGenerator SMIQ are described in Application Notes 1MA03_0E (DECT),1MA04_0E (GSM) and 1MA05_0E (CDMA). Pager signals and signalswith analog modulation are supplied

by Signal Generators SME and SMT.Such signals can also be conditionedby Signal Generator SMIQ to yield therequired fading profiles. ApplicationNote 1MA07_0E shows various solu-tions to this measurement. The applica-tion notes are available from all Rohde& Schwarz representatives under thereader service card number.

Albert Winter

REFERENCES

[1] Mittermeier, W.: Digital Radiocommuni-cation Testers CMD65 and CMD80 – Multi-band and multimode testers for mobile-radiotelephones. News from Rohde & Schwarz(1997) No. 155, pp 6–8

[2] Lüttich, F.: Signal Generator SMIQ + SMIQ-B14 – Fading simulator and signalgenerator in one unit. News from Rohde &Schwarz (1997) No. 155, pp 9–11

Reader service card numbers, see blue box

Application notes

GSM Mobile Tests under Conditions of Fading, CRTP/CRTC + SMIQApplication Note 1MA02_0E Reader service card 158/10

BER Measurements on DECT Receivers under Conditions of Fading, CMD60/65 + SMIQApplication Note 1MA03_0E Reader service card 158/11

BER Measurements on GSM Receivers under Conditions of Fading, CMD55/57 + SMIQApplication Note 1MA04_0E Reader service card 158/12

BER Measurements on CDMA Mobile Radios under Conditions of Fading, CMD80 + SMIQApplication Note 1MA05_0E Reader service card 158/13

SMIQ as Fading Simulator for External Signals, SMIQ + SMIQB1+ SMIQB14Application Note 1MA07_0E Reader service card 158/14

Application notes on fading

Valuables packed safely

State-of-the-art electronics from Rohde & Schwarzwas shown safely packed in edition 10/97 of the customer journal “Knürr direct”. The 19-inchracks and cabinets from Knürr keep out dust, water, heat and electromagnetic interference.Which makes them a safe and sure solution for the integration of high-grade electronics, like TETRA Test System TS8940 (photo far right) fromRohde & Schwarz, comprising TETRA simulatorand TETRA protocol tester. This system was de-signed for verification, quality assurance and typeapproval to TBR35 (Technical Basis for Regulation)of TETRA base and mobile stations. In addition to determination of RF characteristics by the TETRA simulator, TBR35 also stipulates protocolmeasurements, which are performed by the TETRAprotocol tester.

Knürr, with headquarters in Munich and pro-duction facilities in Arnstorf, is an internationallyoperating company and a major supplier of mechanical enclosures for electronics and of technical interior fittings. The company employsabout 1000 persons and achieved turnover ofnearly DM 245 million in 1997. Sö

Reference


Software package COM2000 is a versatile tool allowing data trans-mission with shortwave transceivers of the XK2000 family [1; 2] as well asconfiguration of radiocommunicationprocessors from a PC. TransceiversXK2000 offer the most advanced fea-tures available for shortwave commu-nication and are internationally rec-ognized as representing the higheststandard in quality and technology.Software package COM2000 with itsextra features now rounds off the per-formance of this line of equipment.

Communication or data transfer byshortwave between two stations in-volves a number of complex pro-cesses which are handled automati-cally by radiocommunication proces-sors specially designed for the pur-pose. Thanks to this development,shortwave has turned into a reliabletransmission medium that can also beused by persons without any expertisein the field of radio. Radiocommunica-tion starts with the setting up of a linkto the opposite station.

Continuously changing environmentalparameters such as position of the sunand sunspot activity or different geo-graphical locations limit the use offixed frequencies [3; 4], so special linksetup procedures (automatic link establishment, ALE) were devised.These procedures employ automaticfrequency selection based on variouscriteria and means of analysis. In recentyears the American FED-STD 1045 [5]has established itself as the internationalALE standard and edged most com-pany-specific procedures out of themarket. An exception is the ALIS procedure from Rohde & Schwarz [6],which continues to hold its ground asone of the few alternatives on the market. The shortwave transceivers of the XK2000 family offer both theFED-STD and the ALIS procedure.

A precondition for implementing one ofthe two ALE procedures is a databasecontaining all the required informationabout other stations together with avail-able frequencies as well as checkingand control data. Previously such datahad to be entered on the control panelof the transceiver. Now SoftwareCOM2000 allows convenient entry ofdata from a PC. Aided by the self-explanatory entry menus and detail-ed help function of COM2000, even a user with little experience will find creating an ALE database quitestraightforward (FIG 1). The databasecan be stored as a file or loaded into the transceiver’s radiocommunicationprocessor. The database format is standard, so even computer-controlled

modifications to the frequency pool are possible for example. COM2000 allows the generation of a databasethat, distributed to the other stations, ensures uniform, reliable operation. Different databases and custom controlprograms are obtainable within theCOM2000 software package to suitthe ALE procedure used.

Data exchange with another station requires only a PC with a terminal program in addition to the radio instal-lation. COM2000 offers a programwith a straightforward user interface for reliable transmission and receptionof ASCII and other binary files usingShortwave Transceivers XK2000. In particular, the program supports the input and output of fax files via a faxmachine. Dialog windows are also provided for direct communication intext form with another station. The textentered on the keyboard is displayed inthe top window and sent to the otherstation upon pressing the Enter key. The text received from the other stationappears in the bottom window (FIG 2).

The messages and files sent are compressed prior to transmission andautomatically decompressed by the receiver. This reduces transmission timeand boosts data throughput. Additionaldata link protocols ensure error- and loss-free data transmission. The

Software

COM2000 – the functional software tool for shortwave communication

FIG 2 Terminal program for data exchangeand dialog with opposite station

FIG 1 Frequency pool withfrequencies availablefor link setup


Z-modem protocol is used, meaningthat after any interruption transmissionwill continue from where it was inter-rupted, so that data already transmittedup to this point need not be sent again.

Software package COM2000 is spe-cially tailored to the XK2000 family oftransceivers and is a useful tool for datatransmission by shortwave. It is idealsupport for ALE and designed for dataexchange between individual stations.Despite all the capabilities offered by COM2000, preference should begiven to the PostMan [7] for operating

large networks with higher data volumes.

Thomas A. Kneidel

REFERENCES

[1] Helmke, B.; Wachter, G.: HF TransceiverXK2100 – Digital shortwave for future-proof,long-haul communication. News from Rohde& Schwarz (1994) No. 144, pp 4–7

[2] Träger, R.: HF Transceivers XK2500 andXK2900 – The new members of HF Trans-ceiver Family XK2000. News from Rohde &Schwarz (1997) No. 153, pp 12–13

[3] Waibel, H.; Maurer, P.: PropWiz – Windowsprogram for shortwave link prediction. Newsfrom Rohde & Schwarz (1996) No. 152, pp 46–47

[4] Kneidel, T.; Waibel, H.: New PropWiz software makes shortwave link predictioneven more convenient. News from Rohde &Schwarz (1997) No. 156, p 28

[5] Wicker, G.; Schippan, E.: International ALE(automatic link establishment) standard forHF Transceiver XK2000. News from Rohde& Schwarz (1997) No. 155, pp 19–21

[6] Greiner, G.: Reliable shortwave with ALIS.News from Rohde & Schwarz (1987) No. 116, pp 47– 50

[7] Kneidel, T.: When the PostMan rings on Inter-net. News from Rohde & Schwarz (1997)No. 153, pp 28–29


Software

Test hintReducing time to test GSM base stations

Besides high accuracy and reproducibility of results,speed is of vital importance for in-production testing of GSM900/1800/1900 base stations. Thefollowing transmitter measurements are specifiedfor the transceiver module of a base station:phase/frequency error, carrier power, powerramp, spectrum due to transients and spectrum due to modulation. For the receiver, the bit errorrate is to be determined.

Measurements must be carried out at differentchannel frequencies (usually three). Digital Radio-communication Tester CMD performs these measurements sequentially, taking about 5 min pertest frequency including the setup time for the basestation. If Spectrum Analyzer FSE with GSM Application Firmware FSE-K11 is used in addi-tion, the total measurement time for a base stationcan be considerably reduced by parallelization of test sequences. Prior to starting measurements,

the base station is configured by means of CMD,which then performs the time-consuming BERmeasurements. To obtain reproducible results, asufficient number of frames must be evaluated dueto the random distribution of bit errors. Assumingthat 3000 frames are evaluated, which makes for sufficiently low fluctuation, the measurementtime of CMD will be about 1 min, or 2 min in thecase of two receiver inputs (normal and diversity).During this time FSE can perform the transmittermeasurements of carrier power, spectrum due totransients and spectrum due to modulation.

By optimizing the test sequences with SoftwareFSE-K11, a measurement time of 64 s is achievedfor the measurements carried out by FSE. This isonly slightly longer than the time taken by CMD butit does not contribute to the total measurement time.The remaining time window allows additional

measurements to be carried out, for instance par-tial measurement of spurious emissions or spectrumdue to modulation in the transmit frequency band.This makes for enhanced test depth without extend-ing the total measurement time. The high sensitivityof FSE makes it possible to measure spurious emissions or the spectrum due to modulation in the transmit frequency band without the use of anyadditional equipment (eg bandstop filters) in linewith GSM11.20/11.21 limit values. For further information see Application Note 1MA06_0E,“Reduced Measurement Time for Testing GSMBase Stations through Parallel Use of CMD and FSE/FSE-K11”, which is available from all Rohde& Schwarz representatives.

Roland Minihold

Reader service card 158/16 (CMD), 158/17 (FSE + FSEK11)

Measurementwith CMDonly

Parallelmeasurement

CMD

FSE

Time saved: approx. 1 minper transceiver frequency

Measurement time

Setting time

0 1 2 3 4 5min

Power ramp,phase/frequency error Bit error rate

Time availablefor additionalmeasurements

Carrier power,spectrum due to modulation,spectrum due to transients

Setting time

ROHDE & SCHWARZ

Ext. reference

Ext. trigger

Tx

Coupler

Tx/Rx

Diode detector

Base station with 2 transceivers

Switching matrix

3 dB power divider

CMD FSE


Quantities

Physical phenomena are describedqualitatively and quantitatively by physical quantities. Every value of aquantity can be represented as theproduct of numerical value and unit.Any variation of the unit (eg prefix added to unit) yields a different numer-ical value. The product of numerical value and unit remains constant as it is invariant towards a variation of the unit. Example: V = 0.1 V and V = 100 mV denote the same value of quantity.

Letter symbols for physical quantitiesare stipulated by DIN 1304 and other standards. Letter symbols are to consist of one letter only, since the use of groups of letters would leadto their misinterpretation in equationsas the product of several quantities.For the same reason, abbreviations of names made up of several lettersare not to be used to denote a quantityeither. To signify the special meaningof a letter symbol, an index in the form of letters or numerals may beadded to it.

Quantities of the same kind are given inthe same unit. They are distinguishedby using different letter symbols or the

same letter symbol with index. TABLE 5shows some examples of quantities ofthe same kind.

Equations

The German expressions for quantityequation (Größengleichung), scaledquantity equation (zugeschnitteneGrößengleichung), numerical-valueequation (Zahlenwertgleichung) as well as the relation value_of_quantity =numerical_value_·_unit are based onthe work of Julius Wallot between 1922and 1933. Discussions on this topic cul-minated in the first edition of standardDIN 1313 (1931): Notation of physicalequations.

Quantity equations (DIN 1313) areequations where the letter symbols represent physical quantities or mathe-matical symbols (numerals, variables,functions, operators). Quantity equa-tions are independent of the units chosen. When evaluating quantityequations the letter symbols are to bereplaced by the products of numericalvalues and units. Numerical values andunits in quantity equations are treatedas independent factors. Example: theequation

V = R · I

always yields the same result irrespec-tive of the units used for resistance Rand current I, provided the associatedproducts of numerical value and unitare substituted for R and I.

Scaled quantity equations (DIN 1313)are quantity equations where everyquantity appears with its unit in the denominator. Example:

V/kV = 10–3 · (R/Ω) · (I/A)

The parentheses can be omitted if the assignment of quantities and units is unambiguous, as for example on the left of the equation above or whenhorizontal bars are used.

V R I—— = 10–3 —— ——kV Ω A

The scaled quantity equation has theadvantage that the quotients of quan-tity and unit represent the numerical values related to the given units. Theequations remain correct if the productsof numerical values and units in some other units are substituted for the quantities. In this case however, the units must be converted. The scaledquantity equation is mainly used forrepresenting results.

Numerical-value equations should notbe used any more since they have beenconsidered outdated for over 60 years.According to DIN 1313 they need tobe specially marked as numerical-valueequations and units must be specifiedfor all quantities.

According to the standards, units inbrackets are not to be added to the quantity symbols within equations.Unfortunately, bracketing is widelyspread – it can even be found in manuscripts of university and collegeteachers. Example not to be followed:

V [kV] = 10–3 · R [Ω] · I [A]wrong

Refresher topic

Correct usage of quantities, units and equations (II)

Quantity SI unit

Name Letter symbol Name Symbol

Length l Meter m

Width b Meter m

Height h Meter m

Frequency f Hertz Hz

Resonance frequency fr, frsn Hertz Hz

Bandwidth B, fB Hertz Hz

Electric voltage V Volt V

RMS value of voltage Vrms Volt V

Power P Watt W

Signal power Ps Watt W

Noise power Pn Watt W

Active power P, Pp Watt W

Reactive power Q, Pq Watt W (also Var)

Apparent power S, Ps Watt W (also VA)

TABLE 5 Examples of quantities of same kind X


DIN 1313 rules out this notation. If the quantities in this equation are expressed as products of numerical values and units, the equation does notmake sense, since the units appeartwice as factors. The scaled quantityequation should be used whenever the relation between numerical valuesis to be shown.

Logarithmic quantities, attenuation and gainLogarithmic quantities relate to loga-rithmic ratios of powers or field quantities that define the characteristicsof an object (twoport, eg transmissionelement) [8]. Decibel (dB) is the unitused.

Definition for field quantities (eg for the complex amplitudes of AC voltages):

Voltage attenuation

V1AV = 20 lg|——|dBV2

Voltage amplification, voltage gainV2GV = 20 lg|——|dBV1

Definition for real power quantities (eg active power):

Power gain

P2GP = 10 lg —— dBP1

The arguments of the logarithm arequantities of dimension 1 (numericalvalues). The unit dB is also of dimension1 and is therefore designated as apseudo unit. It is not an SI unit. The function lg designates a logarithm tothe base 10, log stands for the generallogarithmic function.

To be continued.Dr Klaus H. Blankenburg

REFERENCES

[8] DIN 5493-2: Logarithmische Größen und Einheiten, Logarithmierte Größenverhältnisse,Maße, Pegel in Neper und Dezibel (09/94)

Correction: Table 3 of part I of this refresher topicerroneously gives Θ as the symbol for magneticflux. The correct symbol is Φ.

Refresher topic

BooktalkDigital terrestrial television broadcasting

by Paul Dambacher, responsible for strategic mar-keting of broadcasting, paging and broadbandcommunications at Rohde & Schwarz. The bookwas published at the end of 1997/beginning of1998 by Springer of Berlin, Heidelberg, New York.ISBN 3-540-62681-6, 244 pages, 130 illustra-tions, available in English and German. Price approx. DM 98.

The practice-oriented book focuses on all aspectsof digital terrestrial television broadcasting. Theauthor describes its development, the state of ana-log technology, fundamentals of digital technologyand specifications. Implementation with a view tooperation and testing is described in detail andtechnological scenarios of the future are discussed.

The book comprises the following ten chapters:1 History of the development of digital trans-

mission techniques in TV broadcasting2 Present state of the terrestrial television broad-

casting service

3 Basic principles of digital television trans-mission

4 Basic parameters of the specification for thedigital terrestrial TV transmission

5 Program feeds to the digital terrestrial trans-mitting stations

6 Technology of terrestrial DVB transmitters7 Test methods for the digital terrestrial television

transmitter8 Synchronization of the DVB transmitters in a

single-frequency network9 Techniques of measuring the coverage of

digital terrestrial television networks10 Outlook

A detailed list of references and sources (“Newsfrom Rohde & Schwarz” in many instances) as well as a table of abbreviations, formulas and ter-minology round off the publication. The book givesa comprehensive overview of this current topic andis extremely useful for the technical novice and themedia and broadcasting expert alike. Wgr


The overall time required for a computer-controlled measurement is normallymade up of the setting time for the signal source, the DUT settling time, themeasurement time of the instrument, thetime for data transmission and the timefor the controller to run the program.Analyzing the individual componentsreveals weak points and provides cluesfor improvements.

In the following, the time response ofsignal generators controlled via anIEC/IEEE bus is investigated. The timeperiods of interest are shown in FIG 1.In a comparison of RF signal genera-tors, the time required for setting thecarrier frequency (with and without FM)and the carrier level was taken as a typical application. The results are illus-trated in FIGs 2 and 3.

The time for command transmissionvia the IEC/IEEE bus is insignificant in the instruments examined. So anyattempts to reduce this will only

make a modest contribution to faster measurement time.

The major part of measurement time istaken up by internal data processingin the generator (command interpre-tation, limit checks, calculation of set-tings) and by RF signal settling (the twoprocesses are represented as a singlebar in the diagram).

Results confirm the leading position of Signal Generators SME and SMIQfrom Rohde & Schwarz [1; 2] with respect to short setting times, which is essentially due to the fast synthesis of these units.

Development of a new microprocessormodule with a modern 32-bit RISC pro-cessor, integrated in the new SME03Aand SMIQ03A models, has meant afurther substantial reduction of settingtimes, as FIGs 2 and 3 show. The speed advantage makes itself felt in all IEC/IEEE-bus commands and insweeps as well. The new models are fully compatible with the previous ones. All SME models and SMIQ02/03can be upgraded.

For applications requiring only a limitednumber of generator settings, there aretwo interesting modes for extremely fastsetting time: the list mode (in all SMEmodels and in SMIQ02/03/03A) andthe new fast restore mode (in SME03Aand SMIQ03A), which enables random

Panorama

Signal Generators SME03A and SMIQ03A – two milestones on the way to faster measurements

The time needed for IEC/IEEE-bus addressing was approximately thesame for all signal generators; it depends essentially on the controllerand its IEC/IEEE-bus interface.

Con-troller

Mainly determined by

Time componentsin frequency setting(SME02/03 as example)

IEC/IEEE-busaddress-

ing

Controller +signal generator

Transmission viaIEC/IEEE bus

Signal generator

Processing of commandin signal generator

Settling ofRF signal

0.32 ms 0.66 ms 9.2 ms

0.70.7

0.5

8.5

Transmission time

Processing andsettling timewithout FM

Transmission time

Processing andsettling timewith FM

60

50

40

30

20

10

0

27.0

9.2

3.9

0.5 0.5

48.5

ms

Tim

e

Com

petit

or B

Com

petit

or A

SME0

2/03

SMIQ

02/0

3

SME0

3A

SMIQ

03A

3.9

53.3

0.5

36.0

0.7

9.8

0.7

8.5 0.5

2.5 2.42,7

0.5

2.6 2.4

0.70.70.5

8.7

Transmission time

Processing andsettling time

45

40

35

30

25

20

15

10

5

0

7.7

7.6

1.5

2.7

0.5 0.51.7

40.0

ms

Tim

e

Com

petit

or B

Com

petit

or A

SME0

2/03

SMIQ

02/0

3

SME0

3A

SMIQ

03A

SME02/03 SMIQ02/03 SME03A SMIQ03A

List modeSetting time for frequencyand level after trigger pulse 480 µs 570 µs 410 µs 410 µs

Fast restore modeIEC/IEEE-bus transmission time 40 µs 40 µsSetting time (complete setup) 800 µs 600 µs

Setting times (measured) of signal generators in list mode and fast restore mode

FIG 1 Timing diagram forIEC/IEEE-bus settingof signal generator

FIG 2 Measured frequency setting times

FIG 3 Measured level setting times (variationby 20 dB)


Guangdong Mobile CommunicationCorporation (GMCC), the network operator in China with the largest number of mobile-radio subscribers per province at present, contractedRohde & Schwarz to deliver 24 com-plete Coverage Measurement SystemsTS9955. With this project GMCC istaking an important step towards fastexpansion of its mobile-radio networks.The coverage measurement systems are used to plan, optimize and monitorthe quality of GSM900/1800, CDMAand ETACS (extended total access communications) networks. High quality,universal measurement capabilities, theadvanced platform and modular system

concept were the decisive points in selecting the Rohde & Schwarz solution.

The entire instrumentation of the cover-age measurement systems is accommo-dated in a 19-inch rack and installed ina vehicle (FIGs 1 and 2). The systemsare equipped with ultramodern Test Re-ceivers ESVB for highly precise and fastmapping of field strength. Interferenceand reflection measurements in the op-erational GSM network are also pos-sible. Signalling parameters are deter-mined by special test mobiles simulta-neously with field strength and stored inrealtime together with position data col-lected by a satellite navigation system (GPS). The systems are controlled byversatile, easy-to-operate software run-ning under Windows 95. Powerfulevaluation software is in place for sub-sequent processing of measured data.

Johann Maier


Panorama

accessing of up to 1000 stored settingsvia the IEC/IEEE bus (see table in blueBOX). SME03A and SMIQ03A rank as the fastest units worldwide among all IEC/IEEE-bus-controlled RF signal generators.

Kurt Lainer

REFERENCES

[1] Lüttich, F.; Klier, J.: Signal Generator SME:The specialist for digital communications.News from Rohde & Schwarz (1993) No. 141, pp 4–7

[2] Klier, J.: Signal Generator SMIQ – High-quality digital modulation up to 3.3 GHz.News from Rohde & Schwarz (1997) No. 154, pp 4–6

Reader service card 158/18 (SME), 158/19 (SMIQ)

Twenty-four complete mobile-radio coverage measurement systems for China

FIG 2 Coverage Measure-

ment System TS9955installed in vehicle

(VW Sharan)Photo 43 125/1

FIG 1 Coverage Measurement System TS9955 configured around Test Receiver ESVBPhoto 43 125/2


Mobile and cordless phones are high-tech products that are expected to oper-ate reliably and errorfree to standardssuch as GSM, CDMA, TETRA or DECT.The manufacturer has to perform extensive tests during production toguarantee compliance with the aboverequirements. In general terms, the

following steps make up the productionof mobile phones (FIG 1): componentinsertion and soldering of modules,functional test of modules at PCB level,assembly of enclosure, final test of -mobile. The test strategy for series pro-duction of mobile phones calls for testcycles that are as short as possible and

involve minimum effort and expenditure.The objective is to detect production errors caused by incorrect componentplacement, soldering faults or defectivecomponents. To keep repairs to a mini-mum, errors should be detected andeliminated as soon as possible, ie at theend of each production step.

The following typical parameters of the individual modules are determinedfor a GSM mobile phone during RFfunctional testing and RF alignment:Oscillators frequency and phaseVCO circuit voltageAFC stage frequencyRF transmitter RF power, powerstage time template,

frequency and phaseerror, adjacent-channel interference

RF receiver stage bit error rate

Parameters to be checked during the final test are:RF stage AGC adjustment

for power stagesGSM signalling location update,

call setup and cleardown, controlchannel (eg RxLevand RxQual)

Audio section frequency responseDisplay optical features

of display matrixKeypad mechanical functions

Design-specific features usually have to be tested, too. For cordless phones,a test of the wired telecommunicationinterfaces is also required.

As a market leader in the field of digital mobile radio testers, Rohde &Schwarz offers solutions for all thesetests and to all common standards (FIG 2). Complete system solutions forthe production of mobile and cordlessphones are also available, rangingfrom the transport line with fixture stations for contacting the modulethrough test system hardware to specialsoftware for performing the requiredtests. Rohde & Schwarz assumes over-all system responsibility. This meansdefinition of a test concept togetherwith the customer, delivery of testsystem hardware, provision of softwarewith standard test cases and customer-specific test cases, on-site system engineering, adaptation to the con-veyor system, service, remote mainte-nance and calibration. Support forsuch systems is provided throughout theworld.

Erwin Böhler


Panorama

Rohde & Schwarz – a partner for in-productiontesting of mobile phones

Final testInsertion/soldering

Module test Assembly

FIG 2 Digital Radiocommunication Testers CMDhave their notch in mobile phone production toany standard. Photo 42 944/1

FIG 1 Steps in mobile phoneproduction


200-A Four-Line V-Network ENV4200is the latest of Rohde & Schwarz’s V-networks for measuring RFI voltageson power lines that carry very high cur-rents (FIG). This joins the widely used25-A Four-Line V-Network ESH2-Z5covering the frequency range from 9 kHz to 30 MHz [1] and the smaller V-Networks ESH3-Z5 (two-line V-net-work, 16 A, 9 kHz to 30 MHz) andESH3-Z6 (single-line V-network, 150 A,0.1 MHz to 200 MHz) [2].

V-Network ENV4200 is in line with therequirements of CISPR 16-1, VDE 0876and ANSI C 63.4 for V-networks withan impedance of 50 µH || 50 Ω in thefrequency range 150 kHz to 30 MHz.It is based on air-core inductances andcontains an artificial hand.

Background: CISPR 16-1 specifies twotypes of V-networks for the frequencyrange 150 kHz to 30 MHz, one with animpedance of 50 µH || 50 Ω (type 1)and another with an impedance of (50 µH || 5 Ω) || 50 Ω (type 2). Thelatter is also suitable for the frequencyrange 9 kHz to 150 kHz but not for very high currents, since it requires an isolating choke of 250 µH. V-NetworkENV4200 corresponds to type 1,whereas V-Networks ESH2-Z5 andESH3-Z5 are type 2. The maximum current of the V-network is limited by the voltage drop at the standardized inductances (CISPR 16-1 limits the volt-age drop to 5% of the line voltage) andby unavoidable heat generation.

The maximum continuous current on allfour ENV4200 terminals is 100 A withthe fans switched off and 200 A whenthey are switched on. If the internalpower supply is used and the tempera-ture limit is exceeded, the fans switchon automatically.

Key data of V-Network ENV4200 inbrief:• frequency range 150 kHz to 30 MHz,• V-network to CISPR, EN, VDE, ANSI,• impedance 50 µH || 50 Ω,• built-in artificial hand,• continuous current up to 4 x 200 A,• DC resistance per path 6.7 mΩ,• line frequency range 0 to 63 Hz,• maximum permissible line voltage

260 V (voltage to neutral; corre-sponds to 450 V line-to-line voltagein three-phase system),

• air-core design,• built-in pulse limiter,• remote control with TTL levels (com-

patible with Rohde & Schwarz receivers),

• calibrated to CISPR (draft) and ANSIC 63.4.

For connection to the line and DUT,ENV4200 is provided with all-insulatedscrew terminals for taking up cableclamps of sufficient current-carrying capacity.

The phase can be manually selected by means of a front-panel switch or automatically via TTL control inputscompatible with the latest Rohde &Schwarz test receivers. Commercialstandard cables (wired 1:1) with 25-pinCannon connectors can be used ascontrol cables for test receivers of theESxS family (ESHS, ESS, ESPC andESCS) [3]. Special control cables are required for test receivers of theESxI family (ESAI, ESBI and ESMI).

Manfred Stecher

REFERENCES

[1] Brogl, P.: Artificial-mains network ESH2-Z5for measuring interference. News from Rohde& Schwarz (1981) No. 92, pp 30–31

[2] Stecher, M.: Artificial-mains networks forEMC measurements. News from Rohde &Schwarz (1987) No. 117, pp 15–19

[3] Janssen, V.; Weidner, K.-H.: EMI test receiv-ers from 5 Hz to 26.5 GHz – Concept of EMI instrumentation has proven itself. Newsfrom Rohde & Schwarz (1997) No. 156, pp 10–12


Panorama

200-A Four-Line V-Network ENV4200 for measuring RFI voltages at high currents

V-Network ENV4200 for measuring RFI voltageson line connectors with very high currents

Photo 42 884


Rohde & Schwarz is synonymous withelectronic precision and mechanicalperfection. This means a commitment tounite quality and value in a product.Based on this guiding principle the fifthenclosure generation – design 2000 –was developed. The new design meetsall the criteria that modern electronicpackaging has to fulfill, making it fullyin tune with the wide range of T&M andcommunication products from Rohde &Schwarz beyond the year 2000.

Design 2000 is a standardized en-closure system well suited for desktops,for mobile applications and for mount-ing in 19-inch racks to standard DIN 41494. With only a few basic elements, a wide range of enclosurescan be formed, from one to five heightunits and in different widths and depths(FIG 1).

The new system is far more than justpackaging. Besides high stability and all-round protection against severemechanical stresses, the designers paidparticular attention to air-conditioningthe equipment-specific modules and to shielding against electromagneticinterference. With the objective ofachieving low weight, only aluminiumand plastic are used as basic materials.The installation-friendly concept is theresult of close cooperation between designers and specialists from prefabri-cation and final assembly.

The designers proved their ecologicalawareness in the development of design 2000. All current environmentaland recycling criteria for product design were systematically taken intoaccount. This is attested by a certificateawarded for the enclosure system by a well-known recycling enterprise.

A wide range of accessories and spe-cial fittings add to the versatility and

flexibility of design 2000. Besides the19-inch adapters required for rack-mounting, the enclosures can also be equipped with swivel keyboard (FIG 2), extra side-grips and carryingstraps. This is all rounded off by carry-ing handles and robust shock-absorb-ing elements, equipment-specific transitcases and carrying bags.

Harmony between engineering and design was the objective mapped outfor the creation of design 2000, basedon the design rule “Form follows func-tion” and ergonomic aspects. Its indi-vidual look without any frills but with anaura of technology makes design 2000really striking. The interplay of hardedges and soft contours expresses bothtechnical precision and dynamism.Pleasant, light RAL colours in traditionalgreys and blues underline Rohde &Schwarz corporate identity. Togetherwith the new front-panel design, a newenclosure generation has been createdthat will be fit for many years to accom-modate all innovations from Rohde &Schwarz.

It remains to be mentioned that design2000 received the coveted iF ProductDesign Award 1998 and iF EcologyDesign Award 1998from the Industrie Fo-rum Design Hannover.The iF seal for excel-lent design is a prizerecognized through-out the world for in-dustrial products. Forthe consumer it is a reliable indicator of outstanding product quality.

Hans-Dieter König; Helmut Hingrainer

Panorama

Design 2000, the new enclosure system

FIG 1 Design 2000 is a systematic solution: a variety of enclosures can be formed from just a few basic elements. Photo 42 980/3

FIG 2 Swivel keyboard – only one example oflarge number of accessories and special fittingsavailable for design 2000 Photo 42 980/1


Reliable today – reliable tomorrow Broad-casting, paging and broadband communications –no matter whether analog, digital, terrestrial, viacable or satellite – are fields in which Rohde &Schwarz is a partner offering anything from indi-vidual components to complete paging networks,so all the operations and test equipment requiredcan be obtained from this single source.

Info PD 757.3663.21 enter 158/23

Vector Network Analyzer Family ZVR The updated data sheet presents the new analyzers for bidirectional measurements ZVC and ZVCE (20 kHz to 8 GHz) offering largely the same features as ZVR and ZVRE. It also contains themodified order numbers of the ZVR models includ-ing the separate ZVR and ZVRE active and passivetest sets. New options: virtual embedding networkfor ZVR and ZVC (with computer function) and twofour-port adapter models.

Data sheet PD 757.1802.23 enter 158/01

Portable Industrial Controller PSP ExtendedRAM/mass memory (16 Mbyte/≤1 Gbyte). Newoption: 16-Mbyte Memory Extension PSP-B2.


Application Firmware FSE-K10 and FSE-K11 enables complex standard-conforming GSMmeasurements on mobile and base stations at a keystroke.


EMI Package EMI-LINE (150 kHz to 1 GHz) The complete solution for EMC precompliancemeasurements consists of EMI Test Receiver ESPC,Shielded TEM Line S-LINE 700, Software ESPC-K1and cabling; separate US model available.


Quality Management System QUOTIS allowsevaluation of test data and offers repair supportwith learning capability as well as paperless repair. Specifications are listed on insert sheet.

Info PD 757.3757.21Data sheet PD 757.3763.21 enter 158/27

DVB Modulator/Transmitter CT100QT (47 MHzto 862 MHz) modulates IF carriers with MPEG2-coded data streams (16QAM to 256QAM, select-able) and converts them to a fixed RF. ASI and LVDS interfaces and filter module (RF range)available as options.


System Service for T&M and CommunicationsProducts Maximum availability of instruments andsystems is guaranteed by R&S Cologne Plant,the ideal partner for any service requirements.

Info PD 757.3570.21 enter 158/29

Don’t let your DECTective story remain a mystery. For optimum solution of problems occurring in communication with DECT equipment,Rohde & Schwarz with its test facilities, service andsupport is the choice on hand.

Info PD 757.3986.21 enter 158/30

New application notes

GSM Mobile Tests under Conditions of FadingAppl. 1MA02_0E enter 158/10

BER Measurements on DECT Receivers under Conditions of FadingAppl. 1MA03_0E enter 158/11

BER Measurements on GSM Receivers under Conditions of FadingAppl. 1MA04_0E enter 158/12

Level Error Calculation for Spectrum AnalyzersAppl. 1EF36_0E enter 158/31

Measurement of Modulation Spectrum on GSM/DCS/PCS Mobiles acc. to GSM 11.10-1Appl. 1MA01_0E enter 158/32

Synchronization of the Data Rate of TV Test Trans-mitter SFQ with an External ClockAppl. 7MGAN16E enter 158/33

PostMan delivers e-mail messages to places themilkman would never go! This poster presents themessage handling software serving as a wirelesslink to international networks.

Poster PD 757.3670.21 enter 158/34

Schz

Information in print


Newsgrams

EMC symposium in India

An EMC symposium, organized by the Indian institute of EMC en-gineers, was held in Hyderabad inearly December 1997. INCEMIC 97opened with a song in Sanskrit inter-preted by A. R. Sharma, the contentof which unfortunately remained inaccessible to the European par-ticipants. Following this Dr AbdulKalam, parliamentary under-secre-tary and scientific adviser to the defense ministry, spoke of the in-creasing importance of electro-magnetic compatibility, in particularin the military sector.

During the following three days thesubject of EMC was treated frommany different angles before the230 persons attending. Rohde &Schwarz in Munich contributed twolectures. Dr Klaus-Dieter Göpel spokeabout his invention, EMC Test CellS-LINE, which means a considerablesimplification for measurements ofelectromagnetic susceptibility (EMS)and interference (EMI). Karl-OttoMüller expounded the application ofEurope’s EMC directive in memberstates. It was particularly rewardingfor Rohde & Schwarz when thetwelve-man jury selected Dr Göpel’slecture as the best of all 95 contribu-tions and presented him the “BestPaper Award” (photo above).

In the small exhibition accompany-ing the event, Rohde & Schwarz India was the only one of elevenfirms present that not only distributedliterature but also demonstratedmodern EMC instrumentation on its stand. The fact that Rohde &Schwarz co-sponsored INCEMIC 97and invited all participants to lunchin true Indian style on the second day of the symposium all left a verypositive impression of the Munichcompany. AS

Photo: Müller

Rohde & Schwarz – European service partner for Netro of the USA

Rohde & Schwarz Cologne Plantand Netro Corporation of SantaClara in California signed a cooper-ation deal in January 1998. Netrodesigns, produces and sells radio relay equipment. Its products aresuitable for creating both point-to-point and point-to-multipoint linksusing asynchronous transfer mode (ATM). ATM is the most advancedway of implementing bandwidth-intensive data communication in a network. This high-speed data transmission serves new network operators, for example, who supportapplications in municipal networksand offer standard user interfacesfor local network access or a directlink through to the customer.

Rohde & Schwarz Cologne Plant is one of Europe’s biggest servicecenters for electronic test and communications equipment. It offersmaintenance and repair, training,system integration and interfacingplus various other services for infor-mation and communication projects.The deal with Netro covers radio relay project management, on-siteinstallation and engineering sup-port, technical documentation, train-ing, warranty services and repairs.

PI

Expo Comm China South 97

Asia’s leading telecommunicationsand computer show was staged inearly December last year at theGuangzhou China Foreign Trade

Center. It is an event comparable to CeBIT in Germany. As many as10 000 visitors per day came to findout about what is new in the sector,and especially in mobile communi-cation. Mobile phones of every size,shape and colour were presented inanimation and performance shows.Computer software that transmitsand detects script, Internet access,creation of home pages and videoconferencing were also at the focus.International post and telecom corporations – primarily China Telecom, German Telekom, FranceTelecom, Nortel and Telital – wooedthe favour of the visitors, plus big-name producers like Ericsson,Nokia, Motorola, Alcatel, Qualcomand Lucent of course.

Attending from Germany, besidesTelekom, were Siemens, Wandel &Goltermann and Rohde & Schwarz.Li Xunsheng, Liu Albert and Xue Sydney of Rohde & Schwarz China(from left in the photo below) wereable to welcome many visitors at thecompany stand. The communica-tions market in China is boomingand there seems to be no end insight. V. Janssen

Phot

o: J

anss

en

Rohde & Schwarz faculty prizes in Jena

The two founders of Rohde &Schwarz completed their scientificeducation in 1932 when they received their doctorates from thephysics and astronomy faculty ofFriedrich Schiller University. This fa-culty awarded Dr Hermann Schwarzan honorary doctorate in 1992

(sadly Dr Lothar Rohde did not livelong enough to be honoured in the same way). Because of his closeties with the university in Jena, Dr Schwarz instituted prizes to be awarded annually for the bestdissertation and the best thesis in the physics and astronomy faculty.The recipients are selected solely bythe university, without any influenceon the part of Rohde & Schwarz. InJanuary 1998 the prizes, for the bestwork during 1997, were presentedfor the seventh time. The event, presided over by the dean of the faculty, Prof. Roland Sauerbrey, tookplace within a festive colloquium in the renovated auditorium 1 of theAbbeanum in Jena. In his laudatoryspeech for winner Dr Wolf GeroSchmidt, the dean emphasized that the latter, in his dissertation on “The influence of thin metal and passivation layers on the surfaces ofIII-V compound semiconductors”,had produced results far beyondwhat had been expected. They havegreat economic significance for themanufacture of modern componentsfrom such semiconductors becausethey help to increase productionyield through better understandingof atomic structures.

The second prize winner, Falk Ziesche,investigated whether equilibrium potentials, like free energy, containinformation about the rate of decayof instable states. Although Zieschewas only able to get close to the answer, his exceptionally thoroughresearch produced other new find-ings that are being received withgreat interest in scientific circles.

The faculty prizes, presented to Dr Schmidt (left in photo above) and Falk Ziesche (right) by Karl-Otto Müller, demonstrate Rohde &Schwarz’s interest in promoting scientific education. AS

Phot

o: M

ülle

r


Newsgrams

Rohde & Schwarz delivers typeapproval test system to ETS

Within a week of the opening of thenew technology center of the firmElectronic Technology Systems (ETS)in Reichenwalde near Berlin at the beginning of December 1997,Rohde & Schwarz had delivered a GSM System Simulator TS8915 (see News from R&S No. 157, p 28)and put it into operation. The photoabove shows the two directors ofETS, Dr Dietmar Genz (right) andNorbert Kaspar (center), and thesystem in the background. ETS isnow in a position to carry out standard tests and type tests onGSM900/1800/1900 mobile radiostations. The company has been successful internationally since 1995through its capability to perform approval tests for DECT, ISDN andanalog cordless phones as well astests in the EMC sector. D. Blask

Car radio test systems from Cologne

At the end of 1997/beginning of1998 two new car radio test systemsfrom Rohde & Schwarz ColognePlant started operation at MicronasIntermetall in Freiburg and VDO Car Communication in Wetzlar. At Intermetall the fast and precise test system will be used primarily for design optimization. A Signal Generator SMIQ in the system pro-duces digitally modulated World-space data. Use of the Rohde &Schwarz car radio test system isnothing new for VDO, there are already two systems working inquality assurance. The new testsystem is intended for the plannedCar Communication Service Centerin Knoxville, Tennessee in the USA.Activities here will focus on digitalsignal processors and navigationsystems in addition to car radios.

Extra to car radio testing, the systemsoftware supports acquisition of audio quality criteria as well as RDS and VRF parameters on AMand FM receivers and amplifiers,CD, DAT and CR units. Combinedrecording/replay tests, where thesignal can be applied through theFM receiver or a CD unit, allowchecks of compact sets. The audiotest system can be configured withone, two or three signal sources andcustomized for the application.

Further test systems of this kind arealready in use with Karstadt, DelcoElectronics, Interconti and Opel forquality assurance and design opti-mization. H. Heussen


ACCESSNET® trunked radio systems cover India’s big cities

R&S BICK Mobilfunk recently re-ceived an order from Jasmine Telecom India Ltd in New Delhi for ACCESSNET® trunked radiosystems to provide coverage in eight of the country’s biggest cities,including New Delhi, Bombay andCalcutta. “We’re very proud that ourmature and proven ACCESSNET®

system, with its unmatched variety offunctions and features, should havebeen selected by Jasmine Telecom toexpand its offering of radio servicesto the public,” said Heinz Bick, thecompany’s president. “This successin India marks a major milestone in our global marketing strategy.”

PI

Manuals on CD-ROM

Customer documen-tation from the Rohde& Schwarz Test and MeasurementDivision is now being produced onCD-ROM. To begin with, manualsare available for the spectrum analyzers of the FSE family includingthe vector signal analyzer option,with an application note on opera-tion of the IEC/IEEE bus and a number of application programs. Alleditions are in English. The CD-ROMis a complement and alternative tothe printed manual. Integrated userguidance helps the reader find itemsand chapters speedily and simply,and there is a full text index for tracing key terms. The CD-ROMs are produced in pdf format; an installation version of the viewer (Acrobat Reader) is included. Contents can easily be printed out onA4 or US letter paper. CD-ROMs forother equipment families are inpreparation. Dr M. Jetter

30 DAB Analyzers FD1000 for German Telekom

German Telekom has procured itself more than 30 transport framedecoders FD1000 from Rohde &Schwarz to ensure optimum avail-ability of its new transmitter networkfor digital audio broadcasting.FD1000 is used to analyze, monitor,log and record data streams on the ETI (ensemble transport interface) and STI (service transportinterface). ETI and STI data streamsserve for transporting audio signalsin CD quality from a studio via satellite or radio relay link to thetransmitter site.

Other broadcasters like West-deutscher Rundfunk are set to useFD1000 as a key component in operating and monitoring their networks. FD1000 can work as astand-alone or be integrated into the TS6100 monitoring system.

C. Christiansen


TV Monitoring System TS6120 in use at NDR

Following years of working suc-cessfully with the UPKF and TOPASTV monitoring systems, broadcasterNorddeutscher Rundfunk (NDR)again chose tried and tested Rohde& Schwarz technology for an upgrading of its systems. At its 17 largest sites NDR will now monitorand evaluate the availability andquality of terrestrial transmissionswith the TS6120 system (photo below). This system comes with agraphical user interface that is ex-tremely easy to work with and runsunder the MS Windows operatingsystem. NDR is the latest member inthe community of providers world-wide who use this system to monitorboth digital and analog sound andtelevision programs to ensure theircustomers constant availability.

TS6120 is a modular, flexible and future-oriented system offering ca-pability for monitoring upcomingdigital program packages.

C. Christiansen


Phot

o: B

lask


Press comments

The cover theme of issue 4/97 of the electronicsjournal “HF-Report” was measurement of crystalfilter skirt selectivity. The photo showed SignalGenerator SMY (with Spectrum Analyzer FSEB),whose spectral purity and high carrier frequencyaccuracy produce an optimum solution to the application.

The title spread of edition 1/98 of “hf-praxis”, a specialist magazine for RF and microwave engineering, showed a combination of portableMiniport Receiver EB200 and Active Handheld Directional Antenna HE200, a powerful duo forradiomonitoring from 10 kHz through 3 GHzwhile on the move.

Perhaps not the prettiest of testers, but the only onewith a dream 19-inch waistline. That was how “Markt & Technik” presented the small and com-pact Test Workstation TSA on the title page of itsspecial electronics production issue. It fits perfectlyinto any 19-inch environment and satisfies all thedemands made on an advanced test system.

Are you secure?

Frank Backasch, senior editor of “IK – Ingenieurder Kommunikationstechnik”, a magazine for information and communication technology ap-pearing in Berlin, asked his readers this questionin his editorial on the subject of ISDN in issue6/97:

In “a good handful” of cases in the past the BSI(German Information Security Agency) assumesthat there have been determined attempts to pene-trate telecom systems. The BSI was not prepared to

stand by any longer without doing anything aboutit, especially where sensitive applications like theBerlin – Bonn information link are concerned. In an invitation to bid, SIT (corporation for informa-tion technology systems, a subsidiary of Rohde &Schwarz) won out against seven competitors andwas contracted to design the ISDNWall for the BSI.

Focus on R&S spectrum analysis

Spectrum analyzers from Rohde & Schwarz hitthe headlines last November in two major USelectronics magazines. “Microwave Journal” presented Spectrum Analyzer FSEK, while “Microwaves & RF” took a look at the FSE familywith its FSE-B7 option:

FSE plus vector signal analyzer option FSE-B7 is the first high-grade spectrum analyzer whose RF characteristics and the spectral purity of itssynthesizer allow you to measure all parameters in the spectral or time domain and all modulationparameters in the 3.5 and 7 GHz bands.

Multiband and multimode

Measurements in mobile radio continue to be afocal topic. The telecommunications magazine“Frequenz” looked at the subject, and in partic-ular Digital Radiocommunication Tester CMD65,in its 9-10/97 edition:

The spread of multimode cell phones and the wishof service shops as well as producers to be able

to test to different network standards on a cost-efficient basis mean that there is a need for test setswith multistandard capability. Rohde & Schwarz is in place to satisfy the demand. Digital Radio-communication Tester CMD65 can perform meas-urements on GSM, PCN, PCS and DECT mobilephones, while model CMD80 supports CDMA inseveral frequency bands as well as analog AMPS.

DECT product testing

In its title story “Testing DECT products”, the Euro-pean edition 10-11/97 of “Test & Measurement”presented T&M technology for DECT from Rohde& Schwarz:

The protocol testers from Adherent and Rohde &Schwarz demonstrate interesting versatility. Tospeed up time to design and satisfy current marketdemands for a protocol tester, Adherent uses asmuch standard hardware and software as possiblein its ST2002 model. Rohde & Schwarz chooses adifferent approach. The compiler accepts standardtest cases in TTCN and allows the user to write newones in TTCN or C. Holger Jauch of Rohde &Schwarz sees compiling time as being of secon-dary importance compared to the time engineersneed for debugging their own programs: “Mostengineers are not familiar with programming in TTCN, so we’ve opted for C language as anintermediate code. In this way customized test programs can be edited and cleared of errors bothin TTCN and in the C intermediate code.”


Final article

Airspace safety and Austro Control – an excellent combinationMore than 700 000 instrument flightswere safely directed through Austria’sairspace by Austro Control in 1997,with up to 2700 flight activities everyday. Austro Control, with headquartersin Vienna, emerged from the AustrianFederal Office of Civil Aeronautics in1994 and has been kept really busy ever since: “We do everything that inGermany is done jointly by air trafficcontrol, the German MeteorologicalService and the Federal Office of CivilAeronautics”, says Johann Rausch,Chairman of the Board of Directors of Austro Control (FIG 1) who shareshis love of flying with Dr Lothar Rohde,the co-founder of Rohde & Schwarz.Controlling Austrian airspace means avariety of, in part, very complex tasks:surveillance of air traffic, control ofcompliance with air traffic regulations,aeronautical meteorological service,approval of civil aircraft and equip-ment, supervision of aircraft main-tenance, installation and operation ofair traffic control systems, operation ofone of the two meteorological data-bases existing in Europe, and muchmore. To handle all this, Austro Control

employs a staff of about 1000 workingat ten different locations (FIG 2). About300 employees are qualified air trafficcontrollers – modern-day guardian angels so to speak.

Austro Control is highly regarded inter-nationally, and for good reason, be-cause its ATC outfit is among the mostadvanced in the world. It has alreadyintegrated short-term conflict alert forexample, which to date has only beenintroduced by five or six other ATC

bodies worldwide. Air traffic controllerscan draw on special support from VAS(Vienna Air Traffic Control System).Mainframe computers with dual redun-dancy and uninterruptible power sup-

plies collect all relevant data and com-bine them to what is known as the label on radar screens (FIG 3). Austrian air-space is controlled by three medium-range radar systems located at Busch-berg, Feichtberg and Koralpe (FIG 2).

FIG 1 Johann Rausch, Presi-

dent of the AustrianFederal Office of Civil

Aeronautics from 1982to 1994, is Chairman

of the Board of Directors of AustroControl in Vienna.

FIG 2 Austro Control is not only installed at the ATC center in Vienna but also at Austria’s sixmajor airports. It operates three medium-rangeradar stations (MBR).

FIG 3 The calculated label shows the air trafficcontroller the call sign of the aircraft (top), the current and three previous positions (right), climbor descent with current flight altitude (center),flight direction above ground (bottom left) andground speed.

Photo of building: Austro Control


Final article

In such a scenario, reliable radio-communication is of vital importance.Engineer Friedel Geiger (FIG 4), head of telecommunications at AustroControl and responsible for everythingin any way related to voice communi-cation, thinks that the best is just goodenough. To cope with the tremendousincrease in air traffic – roughly 9% per annum during the last ten years –alone in terms of communication, an extensive replacement program iscurrently under way for all single- and6-channel Aeronautical TransmittersSU151 and SU156 from Rohde &

Schwarz procured in 1979. State-of-the-art single-channel transmitters, re-ceivers and transceivers of series 200 (FIG 5) will be installed in theirplace for ACC (area control center),approach control and in the controltowers, this being necessary amongother things because of the newly intro-duced 8.33 kHz channel spacing [1].Rohde & Schwarz won the order notonly because it submitted the best offer.In Geiger’s opinion: “Series 200 ishighly versatile; it’s almost incrediblewhat it’s capable of.” He takes his responsibility very seriously, so he tests all incoming equipment not only to relevant standards but also in an “unconventional way”. “Of course it’s all very well if everything works according to specifications, but for meit’s especially important that transmit-ters, receivers and transceivers shouldshow their mettle in real conditions” (FIG 6). He and his staff are supportedin their work by Rohde & Schwarz test equipment: Radiocommunication

Service Monitors CMS54 and CMS57,Modulation Analyzers FMAV, NetworkAnalyzers ZVR and Spectrum Ana-lyzers FSE [2].

About half of the several hundred unitshad been replaced by the end of 1997,priority being given to sites that espe-cially need capability for 8.33 kHzchannel spacing, for example controlstations for upper airspace. The privatebroadcast stations set up in recentyears are a particular headache for Geiger because of the critical intermod-ulation that they produce in the ATCband. “Unfortunately the special inter-modulation computing program hasn’tbeen around as long as the frequencyallocation plan. It’s not enough just totell a radio operator that he’s causinginterference, we’ve got to prove it.”With VHF-UHF Receivers ESM500 orSpectrum Analyzers FSE from Rohde &Schwarz he is able to gather watertightevidence, “but being right and gettingyour rights are two different things.” As a result Untersberg (Salzburg), afirst-class site for reception, had to beabandoned because of interferenceand the station moved to Feldkirchen.All receiving sites must now be coordi-nated, installed, operated or moved toavoid broadcast stations in the imme-diate vicinity. From headquarters inVienna all receiving sites can be moni-tored and operated by a telecontrolsystem (FIG 7). At the time of our visit,Geiger and his colleagues were busyadapting the interfaces of this system tothe new series 200 equipment.

Geiger and his department have a reliable partner in Rohde & SchwarzAustria (RSÖ). Equipment and softwarefrom Munich are adapted in closecooperation with RSÖ to produce thedesired, tailor-made solution. Deliveriesare being made continuously, and commissioning follows straight on. “We’ve set up an action plan with all steps exactly defined so that the replacement process runs as smoothlyas possible. RSÖ takes care of anyproblems and finds solutions rapidlyand with a great deal of commitment.”

FIG 4 Engineer Friedel Geiger, head of telecommu-nications at AustroControl, had his firstcontacts with Rohde& Schwarz in the early 60s when he began working inthe field of ATC.

FIG 5 A glance into theNorth transmittingcenter at Vienna’sSchwechat airport:series 200 whereveryou look.


Final article

Austro Control is a nonprofit organiza-tion that operates to cover its costs. Rohde & Schwarz direction finders also make a contribution here to the demanding challenges of airspace and air traffic control (FIG 8). In the air too, Austria is a transit country withincreasing volume of traffic. Forecasterssee further growth of 46% during the next five years, so Austro Control is not likely to complain of little to do in keeping things up (in the air) and going.

Christian Rockrohr

REFERENCES

[1] Klarl, H.-G.; Kessler, M.: Series 200 and400U radio equipment – Innovations in ATCradiocommunications: RCMS and 8.33 kHzchannel spacing. News from Rohde &Schwarz (1996) No. 152, pp 14–16

[2] Rohde & Schwarz: Test & Measurement Prod-ucts Catalog 1996/97 (PD 756.3501.25)

FIG 6 Model transmitting/receiving system with series 200 radioequipment at AustroControl headquartersfor approval of voice communication system

FIG 7 All receiving stationsthroughout Austriaare monitored andoperated through a telecontrol systemfrom workstations like this one.

FIG 8 Two direction finders from Rohde &Schwarz at Vienna Schwechat: the old PA007,still working well after 21 years, and the newPA100

Photos: author

Reader service card 158/38 for further informa-tion on series 200 radiocommunication equipment

ROHDE& SCHWARZ GmbH & Co. KG · Mühldorfstraße 15 · D-81671 MünchenP. O. B. 8014 69 · D-81614 München · Tel. (+49 89) 41 29-0 · Fax (+49 89) 41 29-21 64

New

s fro

m R

ohde

& S

chw

arz

158

(199

8/II)

· PD

757

.387

0.21

· B42

622

Visit us on Internet at www.rsd.de

rusn158e

Documents

rohde schwarz number

rohde schwarz gmbh

test systems tsa

universal test system

erwin bhler rohde schwarz

softwaredr klaus

module production

new enclosure system