signal generation back to basicssignal generation back to ... · pdf filewh fm i l d?where are...

Aerospace and Defense Symposium 2007EuMw 2007 Agilent Workshop

Signal Generation Back to BasicsSignal Generation Back to Basics

Beyond S-Parameters© Agilent Technologies, Inc. 2007

Page M6- 1

Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAgenda

The need for creating test signals– Aerospace Defense to Communications

From Generating Signals… No modulation– No modulation

– Analog Modulation– Composite Modulation

T Si l ti Si l…To Simulating Signals– Simulating real-life signals

Signal GeneratorsSignal GeneratorsSignal Simulation Solutions


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopFrom Movies ….

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Walt Disney orders eight audio oscillators (HP 200B) for the sound production of the movie Fantasia.

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Stimulus/Response Testing

OutputInput Output

PowerTone/volumeEqualizer


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAerospace Defense ….

ANTENNA

RF SignalInjection

TESTING RADAR TRANSMITTERS and RECEIVERs

ANTENNA

IF Signal

LNA

IF SignalInjection

1st LO

IFBPF

SignalProcessor

(range and Doppler) 1stIFA

IFBPF

2nd

IFA

2nd

LOLOSubstitution


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopTo Mobile Communications….

TESTING DIGITAL TRANSMITTERS and RECEIVERs

1011001110001010001 1011001110001010001

RF Signal injectionIF Signal Injection

Baseband Signal Injection







Signal GeneratorsSignal GeneratorsSignal Simulation SolutionsSummaryy


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – No Modulation

Continuous Wave (CW)ag

e

Ti age

F

Volta Time

Volta Frequency

Spectrum AnalyzerOscilloscopeThe sine wave is the basic, non-modulated signal: It is useful for stimulus/response testing of linear components and for Local Oscillator substitution Available frequencies range from

Spectrum AnalyzerOscilloscope

Local Oscillator substitution. Available frequencies range from low RF to Millimeter.

RF Microwave MillimeterRF Microwave Millimeter

20-70 GHz 300 GHz6 GHz


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog Modulation

Modulation: Where the Information Resides

V = V(t) sin[2p fc(t) + f(t)]

AM, Pulse FM PM

V = V(t) sin[q(t)]V = V(t) sin[q(t)]


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals - Analog Modulation

Important Characteristics for Modulation

Amplitude ModulationpAmplitude ModulationCarrier

Modulation frequency (rate)Depth of modulation (Mod Index)

Modulation depth %,dB

Volta

ge

Time

Depth of modulation (Mod Index)Linear AM (%)Log AM (dB)Sensitivity (depth/volt)

Modulation frequency

Sensitivity (depth/volt)Distortion %

Where are AM signals used?

AM RadioAM RadioAntenna scanASK (early digital 100101)



Amplitude Modulation

Where are AM signals used?eCarrier

Volta

ge

TimeAM RadioA t

ModulationAntenna scanASK (early digital 100101)



I t t Ch t i ti f

Frequency Modulationge

Important Characteristics for Frequency Modulation

Frequency Deviation

Volta

g

Time

Frequency DeviationModulation FrequencydcFMAccuracyAccuracyResolutionDistortionSensitivity (dev/volt)Wh FM i l d? Sensitivity (dev/volt)Where are FM signals used?

FM RadioAviation Flight systemsAviation Flight systemsRadarFSK (early digital 1011)



V A i [2 f t (t)]

Frequency Modulation

Important Characteristics for

V= A sin[2pfct + m(t)]b

Important Characteristics for Frequency ModulationF /F

dev modb = D

Frequency Deviation

ge

Frequency DeviationModulation FrequencydcFMAccuracy

Volta Time

AccuracyResolutionDistortionSensitivity (dev/volt)Sensitivity (dev/volt)



Important Characteristics for Phase Modulation

Phase Modulation

Phase deviationModulation Rateol

tage

AccuracyResolutionDistortion

Vo Time

DistortionSensitivity

Where are Phase Modulated signals used?

PSK (early digital 1010)PSK (early digital 1010)Radar(pulse coding)



Phase Modulation

Where are Phase Modulated signals used?

PSK (early digital 1010)Radar(pulse coding)Vo

ltage

TimeRadar(pulse coding)



RiseRate=1/T T

Pulse Modulation

On/Off ratio

Risetime

wer

Important Characteristics for Pulse Modulation

TimePulseWidth

t

Po

Pulse widthPulse periodOn/Off ratioOn/Off ratioRise time

Where are Pulse Modulated

1/t

1/Tsignals used?

RadarHigh Power

Pow

erg

Stimulus/ResponseCommunications


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Analog ModulationPulse Modulation

RiRate=1/T T

Where are Pulse Modulated

On/Off ratio

Risetime

wer

Where are Pulse Modulated signals used?

RadarHigh Po er

TimePulseWidth

t

Pow High Power

Stimulus/ResponseCommunications

Width


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite Modulation

Independent Amplitude and

Simultaneous modulation of two Mod Types

Independent Amplitude and Phase

Modulation QIntegrated IQ Modulator

IIndependent pFM and Pulse

Modulation

32 QAM Constellation DiagramFM during the pulse = chirp



P l Di l

Vector Signals (Amplitude and Phase)Polar Display

Phase

0 d0 deg

• Magnitude is an absolute value• Phase is relative to a reference signal (0 degrees)



Vector Signal Changes or Modifications

Phase

0 deg Phase0 deg

Magnitude Change Phase Change

0 deg

Frequency ChangeBoth Change

0 deg


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite ModulationPolar Versus I-Q Format

Q

Project Signals to “I” and “Q” Axes

Q

Polar to Rectangular Conversion

IQ Pl Sh 2 ThiQ-Value

Phase 0 deg IQ Plane Shows 2 ThingsWhat the modulated carrier is doing relative to the

d l t d i

Iunmodulated carrier.What baseband I and Q inputs are required to produce the modulated carrier

I-Value

modulated carrier


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite ModulationTransmitting Digital Data -- Bits vs Symbols

f 1Transmitting Digital Bits (f 1 = 0, f 2 = 1 ) Transmission Bandwidth Required

Binary Data bit = 0,1

f (t) =f 1f 2

T 0101010102/ T

Symbol = Groups/blocks of Bits2 bits/symbol (00 01 10 11) 3 bit / b l (000 001 )

Main lobe width is 2 × Sample rate2/ T

Symbol Rate = Bit rate3 bits/symbol (000 001 …..) 4 bits/symbol (0000 0001 ..)

Symbol 1 (00)

S b l 2 (01)

Symbol Rate = Bit rate# bits per symbol

2/ SMain lobe width is 2 × Symbol rate

Symbol 2 (01)Symbol 3 (10)Symbol 4 (11)

S

f (t) =


Main lobe width is 2 × Symbol rateS


Number of bits per symbol

Transmission bandwidth

Modulation format

Constellation

Digital Modulation Characteristics

BPSK 1 I

Q

01

F

I

Q 0001

QPSK 2

F/2

I1011 F/2

Q 0000

Symbol Rate = #symbols/sec. (Hz)

16 QAM 4

F/4

I



Vector Modulation - Important CharacteristicsQ

IQ Modulation BandwidthFrequency Response/flatness

Q

Frequency Response/flatnessIQ quadrature skewIQ gain balance

Phase 0 degI flatness

Fbw


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopGenerating Signals – Composite ModulationVector Modulation - Where Used

Q

Mobile Digital CommunicationsMobile Digital CommunicationsModern Radars I


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSimulating SignalsAdd interference/impairments to user data

Multipath signals

Multi-path Fading

1011001110001010001 1011001110001010001

Add i l i i tAdd signal impairments Streaming data

Recovering User Data Removing test signal imperfections


g g

Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSimulating Signals

Record/playback real signals scenariosRF Signal

ANTENNA

RF SignalInjection

LNA

1st LO

SignalProcessor

(range and Doppler)IF

BPF

(range and Doppler)1stIFA

2nd

LO

IFBPF

2nd

IFA


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Generators

• Basic CW Signals• Block Diagram (RF and Microwave)• Specifications• ApplicationsApplications

• Analog Signals• Block Diagram (AM, FM, PM, Pulse)• Applications

• Vector Signals • Block Diagram (IQ)• Applications


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block Diagram

Synthesizer Section

RF Source

Frac-N

ALC OutputOutput Section

Phase

ALC Modulator

OutputAttenuator

VCODetector

Reference

divideby X

ALCDriver

ReferenceOscillator ALC Detector

ALC = automatic level controlReference Section


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block Diagram Reference Section

To synthesizer section

PhaseDetector

sectionDivideby X

Optional External Reference Input Reference Oscillator (TCXO or OCXO)

TCXO OCXOC OAging Rate +/- 2ppm/year +/- 0.1 ppm /year

Temp. +/- 1ppm +/- 0.01 ppm

Line Voltage +/- 0.5ppm +/- 0.001 ppm



Front

Synthesizer Section

panelcontrol

N = 93.1

Frac-N

5MHz

Error signal

PhaseDetector

To output sectionX 2

931 MHzVCO

From reference

Multiplier

465 5 MHz

931 MHz

5MHz

From reference section

465.5 MHz



PLL/Fractional-N…suppress phase noise

Overall phase noise of signal Phase-locked-loop (PLL) bandwidth selected for optimum

Referenceoscillator Phase

detector

noise performance

detector noise Broadband

noise floor

20logN

VCO iVCO noise frequency


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Block DiagramOutput Section

ALC Output• ALC

•maintains level output Modulator Attenuator

From synthesizer section

S

power by adding/subtracting power as needed

Source output• Output Attenuator

•mechanical or electronic•provides attenuation to

ALCDriver

pachieve wide output range (e.g. -136dBm to +17dBm)

ALC Detector



Reference Section

Microwave Source

ALC Output

Reference Section

Phase

FracN

Modulatorp

Attenuator

Sampler

VCO

PhaseDet

ALC

Ref Osc

Phase

YIGOscillator

ALC D t t

ALCDriver

SynthesizerFrac-N

PhaseDetector

ALC DetectorSynthesizer Section

Output Section


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications

R F t F

Frequency

Range -- Fmin to FmaxResolution – smallest frequency incrementAccuracy – is it where it says it isy y

r

UncertaintyAccuracy = +_ fCW t aging calt* *

f

Pow

er

Frequency

= CW frequency = 1 GHz= aging rate = 0.152 ppm/year= time since last calibrated = 1 year

fCWt aging

caltq y

Accuracy = 152 Hz+_



• Range ( 136dBm to +17dBm)

Amplitude

• Range (-136dBm to +17dBm)• Accuracy (+/- 0.5dB)• Resolution (0.02dB)• Switching Speed (19ms)• Reverse Power Protection

DUTSource protected from accidental transmission from

How accurate is this number?What is P out?max

DUTaccidental transmission from DUT

Volta

ge

minWhat is P out?

Frequency


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications Frequency Sweep

Ramp sweep• accuracy• sweep time

f2

• sweep time• resolution

t2f1

Step sweep• accuracy

timet2t1

f• accuracy• number of points• switching time

f4f3f2

t4t3t1 t2

f1


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Specifications level accuracy spec

Frequency Sweep - Amplitude

Frequency Sweep• Level Accuracy flatness specpo

wer

• Flatness• Source Match (SWR)

flatness spec

f1 f2frequency

Power Sweep• Power Sweep Range

P2• Power Slope Range• Source Match (SWR)

ower

P2

power sweep range

po

P1

g

t1 t2



Spectral Purity

• Phase Noise• Spurious

CW output

H i

CW output

Non-harmonic spur~65dBc

Harmonic spur~30dBcPhase

noise

Sub-harmonics

0 5 f0 f0 2f0


0.5 f0 f0 2f0


Spectral Purity – Phase Noise

CW output

Measured as

Frequency

Measured as dBc/Hz

Frequency


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – ApplicationsAs a Local Oscillator

IF signal transmitter outputP f

DUT

Poor frequency accuracy and/or resolution will cause the transmitter output to be at the wrong frequency

LO signal

poor phase noise spreads energy into adjacent • Frequency Range

• Accuracy

Key Specs:

channels• Accuracy• Resolution• Output Power• Phase Noise


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications In-Channel Receiver Testing

IF

Receiver SensitivityThe smallest RF signal that will produce a desired baseband output from the

receiver

signal

DUT

in-channel signal(cw signal)

IF Rejection Curvesource output• Range (-136dBm to +17dBm)

Key Specs:

dBm

)

jp

116 dB t

Range ( 136dBm to 17dBm)• Accuracy (+/- 0.5dB)• Resolution (0.02dB)

Frequency

Leve

l (d -116 dBm to –

126 dBm

IF Channel


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications

Receiver SelectivitySpurious Response

Out-of-channel Receiver Testing

IF

Spurious Response Immunity

signalout-of-channel signal(CW and/or modulated signal) DUT

IF Rejection Curvesource output

Key Specs:(d

Bm

)

spur from source and/or high levels of phase noise can cause a good receiver to fail

• Frequency Range • Output Power• Phase Noise

Key Specs:Le

vel (• Phase Noise

• Broadband noise• Non-harmonic spurious


Frequency

Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications

f1

Non-linear Amplifier Testing - TOI

output RF

f1DUT

isolatof2 r

Two-tone IntermodulationK Sf2f

1test system third order products will also fall here

Two tone Intermodulation Distortion• Frequency Range

• Frequency Accuracy• Frequency Resolution

Key Specs:

spurious signals from source can corrupt measurement

q y• Output Power• Non-harmonic spurious

fU = 2f2 - f1fL = 2f1 - f2frequency


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications Out-of-channel Receiver Testing - IMD

IF

Intermodulation immunity

isolator

f1

signal

DUT

isolator

Fmod = nF1 + mF2

n= -1,2

f2

out-of-channel signals IF Rejection Curve

sources output

,m= 2,-1

• Frequency Range • Frequency Accuracy

Key Specs:dB

m)

spur from source

F1 F2 Intermodulation product Fmod = 2F2 – F1

• Frequency Accuracy• Frequency Resolution• Output Power• Non-harmonic spurious

Leve

l (d source


Frequency

Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopBasic CW Signals – Applications Stimulus-Response Testing

Detector

Detector

DUTSweeper Input

Fin Fout

Fin Fout

Fin Fout

Key Specs:• Frequency Range • Frequency Accuracy• Frequency Ramp/step sweep

P

Key Specs:

LO

• Power sweep• Sweep speed• Output Power accuracy• Residual FM



• Basic CW Signals• Block Diagram (RF and Microwave)• Specifications• Applications• Applications

• Analog Signals• Block Diagram (AM, FM, PM, Pulse)Block Diagram (AM, FM, PM, Pulse)• Applications

• Vector Signals • Block Diagram (IQ)• Applications


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAnalog Signals – Block DiagramAdd AM, FM, PM, and Pulse Modulation

ALC Modulator

Pulse

OutputAttenuatorVCO

Freq

PulseMod.

Freq.Control ALC

Driver

ReferenceOscillator

FM, PM input AM input Pulse Mod input


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAnalog Signals – Block Diagram

ALC Output

Add internal modulation generator

ALC Modulator

PulseMod.

AttenuatorVCO

Freq.Control

Mod.

ALCD iDriver

FM, PM inputAM input Pulse Mod input

FMSource

AMSource

PulseSourceReference

Oscillator


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAnalog Signals – Applications

Receiver

Receiver Baseband Distortion

Receiver

In-channel signalIn channel signal(modulated signal)

Non-linear distortion is characterized by• Frequency RangeKey Specs:

Non-linear distortion is characterized by the appearance of harmonics other than

the fundamental component in the baseband output

Frequency Range • Modulation rate/deviation• Modulation Distortion

Required SG M d l ti Receiver ( i (dB)/20)

vel (

dBm

) Distortion

Modulation distortion

= Receiver Distortion % x 10-(margin(dB)/20)

Example:For a receiver distortion of 5% and

Frequency

LevFor a receiver distortion of 5% and

a 10 dB test margin, the SG must have < 1.58% mod distortion


q y

Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopAnalog Signals – Applications

RF Si l

Pulsed Radar Testing with Chirps

ANTENNA

RF SignalInjection

FM during the pulse = chirp

LNA• Frequency Range • FM Modulation rate/deviation

Key Specs:

LNA

1st LO

FM Modulation rate/deviation• Pulse rate, width, rise time

SignalProcessor

(range and Doppler)IF

BPF

(range and Doppler)1stIFA

2nd

LO

IFBPF

2nd

IFA



• Basic CW Signals• Block Diagram (RF and Microwave)

Specifications• Specifications• Applications

• Analog Signalsa og S g a s• Block Diagram (AM, FM, PM, Pulse)• Applications

• Vector Signals • Block Diagram (IQ)• Applications• Applications


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Block Diagram

IQ Modulation

I:

Q 0001

p/Carrier

:

I2

Q 1011:

Good Interface with Digital Signals and CircuitsCan be Implemented with Simple CircuitsF t t t t hFast, accurate state change



OutputI-Q Modulator

Adding the IQ modulator

VCO

SynthesizerOutputI-Q Modulator

p/2

Freq.C t l

ALCControl Driver

Reference

Q

Reference I



Analog Reconstruction Filters

Baseband IQ signal generation

Symbol DAC

Filters

IPattern RAM

yMapping and

Baseband Filters

DAC Q

00 -> 1+j1

1100010110101001011100

00 1 j1

01 -> -1+j1

10 -> -1-j110101010 11 -> 1-j1


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Block DiagramBaseband Generator: Baseband Filters

Fast Transitions Require Wide Bandwidths

Frequency

Frequency

Filtering Slows Down Transitions and Narrows the Bandwidth



OutputI-Q Modulator

Adding an internal Baseband Generator

VCO

SynthesizerOutputI-Q Modulator

p/2

Freq.C t l

ALCControl Driver

QPattern RAM and SymbolReference

DACI

Symbol MappingReference

Baseband Generator

DAC


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopVector Signals – Applications

F t S ifi Si l G ti• Format Specific Signal Generation• Receiver Sensitivity• Receiver Selectivity• Receiver Selectivity• Component Distortion



Digital Format Access SchemesDifferent time - different Users

One User

FDMA Differ channel different UsersFDMA TDMADiffer channel - different Users Different time - different Users

CDMA OFDMSame channel – many users



Format Specific Modulation

GSM: multiple users, same frequency, different time slots



The smallest modulated RF signal that will

Digital Receiver Sensitivity

BasebandRF

DUTThe smallest modulated RF signal that will produce a specified BER from the receiver

Baseband

DSPDAC

RF LO

Payload Data

plitu

deA

mp

BER Spec Line

BER


frequency


T ti 110 dB iti it di it l i

Digital Receiver Sensitivity

Testing a -110 dB sensitivity digital receiver:X= Failed unitO=Passed unit

-110 dB specification-110 dB specification

Set source to 115 dBmActual output power= -114 dBm

XX

X XX

O

-110 dB specificationSet source to -111 dBm

Actual output power= -112 dBm

XX

O OOSet source to -115 dBmO

O

Frequency Frequency

Case 1: Source has +/-5 dB ofoutput power accuracy at-100 to -120 dBm output power.

Case 2: Source has +/-1 dB ofoutput power accuracy at-100 to -120 dBm output power.



• Simulated portionReceiver Sensitivity – Connected Solutions

Demodulator

RF IF

BasebandDe-Coding

A/DConverter

I

QQ

RF/IF BER

DUT

Signal GeneratorSignal

AnalyzerSimulation Software


ySimulation Software


In-channel signal

Receiver Selectivity (Blocking Tests)g

(modulated signal)

BasebandRF

O t f h l i l

DSP

RF LO

DAC

IF Rejection Curve

Out-of-channel signal(CW or modulated signal)

Payload

vel (

dBm

)

Spur from source and/or high levels of phase noise can cause a good receiver to fail

Data

F

Lev

Sensitivity specification


Frequency


Component Distortion – Adjacent Channel Power Ratio

Spectral Output from amplifier

DUT

Input from VSG

p p p

ACPR

Spectral regrowth

ACP Margin

Margin (dB) 0 1 2 3 4 5 10 15Error contribution (dB) 3.0 2.5 2.1 1.8 1.5 1.2 0.4 0.2



OFDM Si l

Component Distortion – Error Vector Magnitude

OFDM Signal -400 MHz Bandwidth

DAC

QQ QQ

Q Magnitude Error (IQ error mag)

II

Error Vector MagnitudeTest

Signal

Ideal (Reference) Signal

Phase Error (IQ error phase)

f


I


Measured EVM = -30 dB, 3.3%Component Distortion – EVM


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation Solutions

Simulating real signal environmentsSignal CreationSignal Creation

Import/export Custom Digital Data User

H d

Create Impairments

Digital

Fading Baseband

SWHardware

RF/Microwave SignalsI t l BBGStream Data

Waveform Capture and

Playback Baseband

Digital Signal

Interface

Si l

RF/Microwave SignalsInternal BBGStream Data

External BBG

Baseband SW Baseband IQ generation

Vector Signal

Generator

Remove test signal imperfections

Signal Creation

SWCreate Standard

Signals

pe ect o sVector Signal

Analyzer



Remove Test Signal Imperfections

BBG

Add

Signal LAN/GPIB

Add Predistortion (corrections)

VSGSoftware LAN/GPIB

Measure Measurement

Results

VSA

Modulated Signal



Remove Test Signal Imperfections – IQ Flatness

Source of error – I/Q modulator, RF chain, IQ pathResult passband tilt ripple and roll offResult – passband tilt, ripple, and roll off


Aerospace and Defense Symposium 2007EuMw 2007 Agilent WorkshopSignal Simulation SolutionsRemove Test Signal imperfections – IQ flatness

Solution – measure vector signal generator and apply predistortionTradeoff – calculation time, valid cal time Typical application – wideband, multitone, and multicarrier

500 MHz UWB32 tones - 80 MHz

Before2.4 dB 6-8 dB

0.1 dB < 3 dBAfter

0.1 dB < 3 dB



Removing Test Signal Imperfections - IMD

Before Predistortion After PredistortionBefore PredistortionMeasured in-band IMD = -40 dBc

After PredistortionMeasured in-band IMD = -84 dBc



Removing Test Signal Imperfections – Group Delay Before Predistortion

EVM -30 dB, 3.3%After Predistortion

EVM –34 dB, 2%



DUT

Non-linear Amplifier Testing

output RFDUT

Intermodulation Di t tiDistortion

• Improved IMD suppression (typically > 80 dBc) Correct generator with additional devices in the loop

Signal Studio – Enhanced Multitone

• Correct generator with additional devices in the loop• Lower overall cost-of-test for large # tones• Same hardware for ACPR/NPR distortion tests

Up to 1024 tones Set relative tone powerSet relative tone phase 80 MHz correction BWCCDF plot


p


Adding Impairments to Signals – Fading

R i

Faded signal

Receiver

��

BER/PER analysis

transmission channel

Interferersanalysis

SW and interface hw Faded analog RF, IF, or IQ for receiver testFaded digital IQ baseband for digital

subsystem test



RF Signal

RF Capture & Playback

ANTENNA

RF SignalInjection

LNA

1st LO

Record signals off the airTransfer files to a PC equipped with Baseband Studio and re-formatSt th i t th V t PSG i l t f l b k

IF

SignalProcessor

(range and Doppler)1stIF2nd

Stream them into the Vector PSG signal generator for playback

IFBPF

1stIFA

2nd

LO

IFBPF

2nd

IFA



Digital Capture & PlaybackCapture data from the digital

Digital bus

Capture digital I/Q signals

p gsection of a transmitter

DUT

Test stimulus to the digital section of a receiver

Digital bus

Playback digital I/Q signals

section of a receiver

DUT


Aerospace and Defense Symposium 2007EuMw 2007 Agilent Workshop

THANK YOU!THANK YOU!


signal generation back to basicssignal generation back to ... · pdf filewh fm i l d?where are...

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