INDUSTRIAL TRAINING REPORTON

SRE-RADAR TESTING AND TRANSMITTER

[28 May 2012 - 07 July 2012]

Under the supervision of

Mr. R N Tyagi

(Training Incharge)

Deputy Manager,HRD,BEL

Name of Organisation : Bharat ElectronicsAddress of Organisation : Bharat Electronics Ltd,Bharat Nagar

Vaishali,Ghaziabad,U.P

Submitted By:-

ANUBHAV KUMAR SAURAV

Electronics & Communication Engineering

Enrollment No: 09102346

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JAYPEE INSTITUTE OF INFORMATION TECHNOLOGY, NOIDA

ACKNOWLEDGEMENT

I wish to express my sincere thanks to the Management of Bharat Electronics Limited (BEL),

Bharat Nagar, Ghaziabad including the Head of the Human Resource Development

Department Mrs. VANITA BHANDARI (MANAGER, HRD) for providing me an

opportunity to receive training in this important Industrial Unit manufacturing electronics

equipment in our country.

I am deeply indebted to Mr. DHYAN SINGH , (Deputy General Manager, Radar Division

PA-R2) AND Mr. A.K. SAKSENA (Manager,PA-R2) for sparing his most special time in

providing guidance to me in training. Without his wise counsel, inestimable encouragement,

it would have been difficult for me to have knowledge of the functioning of various types of

electronics equipment particularly radars. Gratitude is also due to him for his constant

guidance and direction in writing this piece of work.

Special thanks to Mr. DINESH KUMAR (Department of Radar Transmitter) for their

valuable guidance, help and cooperation.

It is a great pleasure to express my heart full thanks to staff of BEL who helped me directly

or indirectly throughout the successful completion of my training. There is no substitution to

‘Team Work’; this is one of the lessons I learnt during my training in BHARAT

ELECTRONICS LIMITED.

Signature of the student:………………………… Date : ……………...................

Name of the student : Anubhav Kumar Saurav (09102346)

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CERTIFICATE

This is to certify that Anubhav Kumar Saurav of B.TECH 3RD YEAR(ECE) of JIIT ,

NOIDA has successfully completed his industrial training under guidance of Mr.

A.K.Saxena, Manager(PA-RADAR) and Mr. Dinesh Kumar in BHARAT ELECTRONICS

LIMITED, GHAZIABAD from 28th may to 7th July 2012.

A project titled SRE-RADAR TESTING & TRANSMITTER was assigned to him in this

period. He worked hard and diligently and completed his project in time. He took lot of

initiative in learning about RADAR SYSTEM AND VARIOUS TEST

INSTRUMENTS/METHODS. His overall performance during the project was excellent.

We wish him all success in his career.

Mr.Dinesh kumar Mr. A.K.Saxena

Deptt. Of Radar Tx. Manager

(PA-RADAR2) (PA-RADAR2)

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CONTENTS

S.No. Topics Page Nos.

1 BEL Introduction 5

2 BEL (Ghaziabad Unit) 6

3 Product Ranges 7

4 Services of BEL 8

5 Rotation Program 8-15

Test Equipment and Automations

PCB Fabrication

Quality Control Works-Radar

Work Assembly-Communication

Magnetics

Microwave Lab

7 Radar 16

8 Different Types of Radar 20

9 Radar Application 22

10 Radar Transmitter 23

11 Radar Subsystem 25

12 Conclusions &References 33

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INTRODUCTION

Bharat Electronics Limited (BEL) was established in 1954 as a public Sector Enterprise under the administrative control of Ministry of Defence as the fountainhead to manufacture and supply electronics components and equipment. BEL, with a noteworthy history of pioneering achievements, has met the requirement of state-of-art professional electronic equipment for Defence, broadcasting, civil Defence and telecommunications as well as the component requirement of entertainment and medical X-ray industry.

Having started with a HF receiver in collaboration with T-CSF of France, the company’s equipment designs have had a long voyage through the hybrid, solid-state discrete component to the state of art integrated circuit technology. It moved on to semiconductors with the manufacture of germanium and silicon devices and then to the manufacture of Integrated circuits. The design groups have CADD facility; the manufacturing has CNC machines and a Mass Manufacture Facility. QC checks are preformed with multi-dimensional profile measurement machines, Automatic testing machines, environmental labs to check extreme weather and other operational conditions.

Today BEL’s infrastructure is spread over nine locations with 29 production divisions having ISO-9001/9002 accreditation. Its manufacturing units have special focus towards the products ranges like Defence Communication, Rader’s, Optical & Opto-electronics, Telecommunication, sound and Vision Broadcasting, Electronic Components, etc. BEL offers a variety of services like Telecom and Rader Systems Consultancy, Contract Manufacturing, Calibration of Test & Measuring Instruments, etc. At the moment, the company is installing MSSR radar at important airports under the modernization of airports plan of National Airport Authority (NAA).

BEL was among the first Indian companies to manufacture computer parts and peripherals under arrangement with International Computers India Limited (ICIL) in 1970s. BEL was ranked No. 1 in the field of Electronics and 46th overall among the top 1000 private and public sector undertakings in India by the Business Standard in its special supplement “The BS 1000 (1997-98)”. BEL was listed 3rd among the Mini Rattan’s (Category II) by the Government of India, 49th among Asia’s top 100 worldwide Defence Companies by the Defence News, USA.

CORPORATE MOTTO, MISSION AND OBJECTIVES:

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The passionate pursuit of excellence at BEL is reflected in a reputation with its customers that can be described in its motto, mission and objectives:

CORPORATE MOTTO : “Quality, Technology and Innovation.”

CORPORATE MISSION : To be the market leader in Defence Electronics and in other chosen fields and products.

CORPORATE OBJECTIVES

To become a customer-driven company supplying quality products at competitive prices at the expected time and providing excellent customer support.

To achieve growth in the operations commensurate with the growth of professional electronic industry in the country.

To generate internal resources for financing the investments required for modernization, expansion and growth for ensuring a fair return to the investor.

In order to meet the nations strategic needs, to strive for self-reliance by indigenization of materials and components.

To retain the technological leadership of the company in Defence and other chosen fields of electronics through in-house research and development as well as through Collaboration/Co-operation with Defence/National Research Laboratories, International Companies, Universities and Academic Institutions.

To progressively increase overseas sales of its products and services. To create an organizational culture which encourages members of the organization to real

and through continuous learning on the job

BEL GHAZIABAD UNIT

Formation: In the mid 60’s, while reviewing the Defence requirement of the country, the government focused its attention to strengthen the Air Defence system, in particular the ground electronics system support, for the air Defence network. This led to the formulation of a very major plan for an integrated Air Defence Ground Environment System known as the plan ADGES with Prime Minister as the presiding officer of the apex review committee .At about the same time, Public attention was focused on the report of the Bhabha committee on the development and production of electronic equipment. The ministry of Defence immediately realized the need to establish production capacity for meeting the electronic equipment requirements for its plan ADGES.

BEL was then inserted with the task of meeting the development and production requirement for the plan ADGES and in view of the importance of the project it was decided to create additional capacity at a second unit of the company. In December 1970 the Govt. sanctioned an additional unit for BEL. In 1971, the industrial license for manufacture of radar

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and microwave equipment was obtained, 1972 saw the commencement of construction activities and production was launched in 1974.

Over the years, the unit has successfully manufactured a wide variety of equipment needed for Defence and civil use. It has also installed and commissioned a large number of systems on turnkey basis. The unit enjoys a unique status as manufacture of IFF systems needed to match a variety of primary raiders. More than 30 versions of IFF’s have already been supplied traveling the path from vacuum technology to solid-state to latest Microwave Component based system.

PRODUCT RANGES

The product ranges today of the company are:

RADAR SYSTEMS 3-Dimensional High Power Static and Mobile Radar for the Air Force. Low Flying Detection Radar for both the Army and the Air force. Tactical Control Radar System for the Army. Battlefield Surveillance Rader for the Army. IFF Mk-X Radar systems for the Defence and export. ASR/MSSR systems for Civil Aviation. Radar & allied systems Data Processing Systems.

COMMUNICATIONS Digital Static and Mobile Tropo scatters Communication Systems for the Air Force. VHF, UHF & Microwave Communication Equipment. Bulk Encryption Equipment. Turnkey communication Systems Projects for Defence & civil users. Static and Mobile Satellite Communication Systems for Defence. Telemetry /Tele-control Systems.

ANTENNA Antennae for Radar, Terrestrial & Satellite Communication Systems. Antennae for TV Satellite Receive and Broadcast applications. Antennae for Line-of-sight Microwave Communication Systems.

MICROWAVE COMPONENT Active Microwave components like LNAs, Synthesizer, and Receivers etc. Passive Microwave components like Double Balanced Mixers, etc.

SERVICES OF BHARAT ELECTRONICS LIMITED (BEL):-

DEFENCE PRODUCTS:-

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Naval System

Military Communication Equipment

Radars

Tele Communication & Broadcasting Services

Opto Electronics

Tank Electronics

NON-DEFENCE PRODUCTS:-

Electronic Voting Machine

Solar Products

Simputer

DTH

ROTATION PROGRAM

Under this students are introduced to the company by putting them under a rotation program to various departments. The several departments where I had gone under my rotational program are:

1. Test Equipment and Automation2. P.C.B. Fabrication3. Quality Control Works-Radar4. Work Assembly- Communication5. Magnetics6. Microwave lab

Rotation period was to give us a brief insight of the company’s functioning and knowledge of the various departments. A brief idea of the jobs done at the particular departments was given. The cooperative staff at the various departments made the learning process very interesting , which allowed me to know about the company in a very short time.

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TEST EQUIPMENT AND AUTOMATION

This department deals with the various instruments used in BEL. There are 300

equipments and they are of 16 types.

Examples of some test equipments are:

Oscilloscope(CRO)

Multimeter

Signal Analyzer

Logical Pulsar

Counter

Function Generator etc.

Mainly the calibration of instruments is carried out here. They are compared with the

standard of National Physical Laboratory (NPL). So, it is said to be one set down to NPL. As

every instrument has a calibration period after which the accuracy of the instrument falls

from the required standards. So if any of the instruments is not working properly, it is being

sent here for its correct calibration. To calibrate instruments software techniques are used

which includes the program written in any suitable programming language. So it is not the

calibration but programming that takes time .For any industry to get its instrument calibrated

by NPL is very costly, so it is the basic need for every industry to have its own calibration

unit if it can afford it.

Test equipment and automation lab mainly deals with the equipment that is used for testing

and calibration .The section calibrates and maintains the measuring instruments mainly used

for Defence purpose.

A calibration is basically testing of equipment with a standard parameter. It is done with the

help of standard equipment should be of some make, model and type.

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The national physical laboratory (NPL), New Delhi provides the standard values

yearly. BEL follows International Standard Organization (ISO) standard. The test equipments

are calibrated either half yearly or yearly.

After testing different tags are labeled on the equipment according to the observations.

1. Green –O.K , Perfect

2. Yellow – Satisfactory but some trouble is present.

3. Red – Can’t be used, should be disposed off.

The standard for QC, which are followed by BEL are:

1. WS 102

2. WS 104

3. PS 520

4. PS 809

5. PS 811

6. PS 369

Where, WS = Workmanship & PS = Process Standard

After the inspection of cables, PCB’s and other things the defect found are given in following

codes.

A --- Physical and Mechanical defects.

B --- Wrong Writing

C --- Wrong Component / Polarity

D --- Wrong Component / Mounting

E --- Bad Workmanship/ Finish

F --- Bad Soldering

G --- Alignment Problem

H --- Stenciling

I --- Others (Specify)

J --- Design & Development

After finding the defect, the equipment is sent to responsible department

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which is rectified there.

P.C.B. FABRICATION

P.C.B. stands for Printed Circuits Board. It’s an integral part of the Electronics equipment as well as all the components are mounted on it. It consists of the fiberglass sheet having a layer of copper on both sides.

TYPES OF PCBs

Single Sided Board : Circuits on one side. Double Sided Board : Circuit on Both side. Multi-layer Board : Several layers are interconnected through hole metallization

QUALITY CONTROL

According to some laid down standards, the quality control department ensures the

quality of the product. The raw materials and components etc. purchased and inspected

according to the specifications by IG department. Similarly QC work department inspects all

the items manufactured in the factory. The fabrication department checks all the fabricated

parts and ensures that these are made according to the part drawing, painting , plating and

stenciling etc are done as per BEL standards.

The assembly inspection departments inspects all the assembled parts such as PCB ,

cable assembly ,cable form , modules , racks and shelters as per latest documents and BEL

standards .

The mistakes in the PCB can be categorized as:

D & E mistakes

Shop mistakes

Inspection mistakes

The process card is attached to each PCB under inspection. Any error in the PC is

entered in the process card by certain code specified for each error or defect.

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After a mistake is detected following actions are taken:

1. Observation is made.

2. Object code is given.

3. Division code is given.

4. Change code is prepared.

5. Recommendation action is taken

WORK ASSEMBLYWORK ASSEMBLY

This department plays an important role in the production. Its main function is to assemble

various components, equipments and instruments in a particular procedure.

It has been broadly classified as:

WORK ASSEMBLY RADAR e.g. INDRA –II, REPORTER.

WORK ASSEMBLY COMMUNICATION e.g. EMCCA, MSSR, MFC.

EMCCA: EQUIPMENT MODULAR FOR COMMAND CONTROL APPLICATION.

MSSR: MONOPULSE SECONDARY SURVEILLANCE RADAR.

MFC: MULTI FUNCTIONAL CONSOLE.

The stepwise procedure followed by work assembly department is:

o Preparation of part list that is to be assembled.

o Preparation of general assembly.

o Schematic diagram to depict all connections to be made and brief idea about all components.

o Writing lists of all components.

In work assembly following things are done :

M aterial Receive :

Preparation- This is done before mounting and under takes two procedures.

Tinning- The resistors ,capacitors and other components are tinned with the help of tinned

lead solution .The wire coming out from the components is of copper and it is tinned nicely

by applying flux on it so that it does not tarnished and soldering becomes easy.

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Bending- Preparation is done by getting the entire documents , part list drawing and bringing

all the components before doing the work.

Mounting- It means soldering the components of the PCB plate with the help of soldering

tools. The soldering irons are generally of 25 W and are of variable temperature, one of the

wires of the component is soldered so that they don’t move from their respective places on

the PCB plate. On the other hand of the component is also adjusted so that the PCB does not

burn.

Wave Soldering- This is done in a machine and solder stick on the entire path, which are

tinned.

Touch Up- This is done by hand after the finishing is done.

Cleaning:

Inspection- This comes under quality work.

Heat Ageing- This is done in environmental lab at temperature of 40 degree C for 4 hrs and

three cycles.

Testing:

Lacquering- This is only done on components which are not variable.

Storing- After this variable components are sleeved with Teflon. Before Lacquering mounted

plate is cleaned with isopropyl alcohol. The product is then sent to store.

MAGNETICS

In this department different types of transformers and coils are manufactured , which are used in the various Defence equipments i.e. radar , communication equipments. This department basically consists of three sections :

1.) PRODUCTION CONTROL :- Basic function of production control is to plan the production of transformer and coils as per the requirement of respective division (Radar and Communication). This department divided into two groups :(a) Planning and (b) Planning store .

2.) WORKS (PRODUCTION) :- Production of transformers and coils are being carried out by the works departments.

3.) QUALITY CONTROL :- After manufacturing the transformer/coils the item is offered to the inspection department to check the electrical parameters(DCR , No load

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current , full load current , dielectric strength , inductance , insulation resistance and mechanical dimension as mentioned in the GA drawing of the product.

The department provides the information about manufacturing a coil and transformer.The various types of transformers are as follows :

1. Air cored transformers2. Oil filled transformers3. Moulding type transformers4. P.C.B Mounting transformers :-

(a) Impedance matching transformers(b) RF transformers(c) IF transformers

The various types of cores are as follows :1. E type2. C type3. Lamination4. Ferrite core5. Toroidal core

Steps involved in the process of manufacturing of transformer/coils:

Preparation of former : Former is made of plastic bakelite comprising a male and female plates assembled and glued alternately to form a hollow rectangular box on which winding is done.

Winding : It is done with different material and thickness of wire. The winding has specified number of layers with each layer’s having a specified number of turns. The distance between the two turns should be maintained constantly that is there should be no overlapping. The plastic layer is inserted between two consecutive layers.

The various types of windings are as follows :

Layer Winding Wave Winding Bank Winding

Insulation : For inter-winding and inter layer , various types of insulation sheets viz. Craft paper , paper , leather , oil paper , polyester film are being used.

Protection : To protect the transformer from the external hazards , moisture , dust and to provide high insulation resistance , they are impregnated.

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MICROWAVE LABORATORY

Microwave lab deals with very high frequency measurements or very short wavelength

measurements. The testing of microwave components is done with the help of various radio

and communication devices. Phase and magnitude measurements are done in this section.

Power measurements are done for microwave components because current and voltage are

very high at such frequencies.

Different type of waveguides is tested in this department like rectangular waveguides,

circular waveguides. These waveguides can be used to transmit TE mode or TM mode. This

depends on the users requirements. A good waveguide should have fewer loses and its walls

should be perfect conductors.

In rectangular waveguide there is min. distortion. Circular waveguides are used where

the antenna is rotating. The power measurements being done in microwave lab are in terms of

S- parameters. Mainly the testing is done on coupler and isolators and parameters are tested

here.

There are two methods of testing:

a.) Acceptance Test Procedure(ATP)

b.) Production Test Procedure(PTP)

Drawing of various equipments that are to be tested is obtained and testing is

performed on manufactured part. In the antenna section as well as SOHNA site various

parameters such as gain ,bandwidth ,VSWR , phase ,return loss, reflection etc. are checked.

The instruments used for this purpose are as follow:

i) Filters

ii) Isolators

iii) Reflectors

iv) Network Analyzers

v) Spectrum Analyzers

vi) Amplifiers and Accessories

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RADAR

The term RADAR was coined in 1941 as an acronym for Radio Detection and Ranging. This acronym of American origin replaced the previously used British abbreviation RDF (Radio Direction Finding).

Radar is a system that uses radio waves to detect, determine the distance or speed, objects such as aircraft, ships, rain and map them. Speed detection is measured by the amount of Doppler Effect frequency shift of the reflected signal. A transmitter emits radio waves, which are reflected by the target, and detected by a receiver, typically in the same location as the transmitter. Although the radio signal returned is usually very small, radio signals can easily be amplified, so radar can detect objects at ranges where other emission, such as sound or visible light, would be too weak to detect. Radar is used in many contexts, including meteorological detection of precipitation, air traffic control, police detection of speeding traffic, and by the military.

BASIC PRINCIPLE : Echo and Doppler Shift

Echo is something you experience all the time. If you shout into a well or a canyon, the echo comes back a moment later. The echo occurs because some of the sound waves in your shout reflect off of a surface (either the water at the bottom of the well or the canyon wall on the far side) and travel back to your ears. The length of time between the moments you shout and the distance between you and the surface that creates the echo determines the moment that you hear the echo.

Doppler shift is also common. You probably experience it daily (often without realizing it). Doppler shift occurs when sound is generated by, or reflected off of, a moving object. Doppler shift in the extreme creates sonic booms. Here's how to understand Doppler

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shift. Let's say there is a car coming toward you at 60 miles per hour (mph) and its horn is blaring. You will hear the horn playing one "note" as the car approaches, but when the car passes you the sound of the horn will suddenly shift to a lower note. It's the same horn making the same sound the whole time. The change you hear is caused by Doppler shift.

HOW RADAR WORKS

A radar system, as found on many merchants’ ships, has three main parts:

1. The antenna unit or the scanner2. The transmitter receiver or ‘transceiver’ and

3. the visual display unit

The antenna is two or three meter wide and focuses pulses off very high frequency radio energy into a narrow vertical beam. The frequency of the radio waves is basically about 10,000 Mhz. The antenna is rotated at the rate of 10 to 25 rpm so that radar beam swaps through 300degree Celsius all around the sky out to a range of about 90 kms.

In all radar it is vital that the transmitting and the receiving in a transceiver are in close harmony. Every thing depends on accurate measurement of the time that passes between the transmission of pulse and the return of the echo. About 1000, pulses per second are transmitted. Though it is varied to suit the requirements. Short pulses are best for short-range work, longer pulses are best for longer-range work.

An important part of transceiver circuit is ‘modular circuit’. This ‘keys’ the transmitter so that it oscillates, or pulses for the right length of time. The pulses so designed are ‘video pulses. These pulses are short range pulses hence can’t serve out the purpose of long range work .In order to modify these pulses to long range pulses or the RF pulses, we need to generate the power. The transmitted power is generated in a device called the “magnetron” which can handle all these short pulses and very high oscillations.

The basic idea behind radar is very simple: a signal is transmitted, it bounces off an object and some type of receiver later receives it.  They use certain kinds of electromagnetic waves called radio waves and microwaves.  This is where the name RADAR comes from (Radio Detection And Ranging).  Sound is used as a signal to detect objects in devices called SONAR (Sound Navigation Ranging).  Another type of signal used that is relatively new is laser light that is used in devices called LIDAR (Light Detection And Ranging).             

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Basic Radar System:

Some radar transmitters do not transmit constant, uninterrupted electromagnetic waves.  Instead, they transmit rhythmic pulses of EM waves with a set amount of time in between each pulse.  The pulse itself would consist of an EM wave of several wavelengths with some dead time after it in which there are no transmissions.  The time between each pulse is called the pulse repetition time (PRT) and the number of pulses transmitted in one second is called the pulse repetition frequency (PRF).  The time taken for each pulse to be transmitted is called the pulse width (PW) or pulse duration.  Typically they can be around 0.1 microseconds long for penetrating radars or 10-50 microseconds long for imaging radars (a display. microsecond is a millionth of a second).

PRT = 1 / PRF

RT means repetition time.

However, the above diagram is not quite realistic for several reasons.  One reason why it is not realistic is that the frequency in waves of the pulses is the same.  In real life the frequency of the waves are not the same and they change as time goes on.   This is called frequency modulation, which means the frequency changes or modulates.

It looks something like this...

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Think of this as one pulse.  All the pulses will look something like this.

On the above diagram, the frequency of the wave is low on the left and it slowly increases, as you look right.  The different frequencies of the wave will lie in a range called bandwidth.  Radars use bandwidth for several reasons regarding the resolution of a data image, memory of the radar and overuse of the transmitter.  For instance, a high bandwidth can yield a finer resolution but take up more memory. When an EM wave hits a surface, it gets partly reflected away from the surface and refracted into the surface.  The amount of reflection and refraction depends on the properties of the surface and the properties of the matter, which the wave was originally traveling through.  This is what happens to radar signals when they hit objects.  If a radar signal hits a surface that is perfectly flat then the signal gets reflected in a single direction (the same is true for refraction).  If the signal hits a surface that is not perfectly flat (like all surfaces on Earth) then it gets reflected in all directions.  Only a very small fraction of the original signal is transmitted back in the direction of the receiver.  This small fraction is what is known as backscatter.  The typical power of a transmitted signal is around 1 kilowatt and the typical power of the backscatter can be around 10 watts.

TYPES OF RADAR

Based on function radar can be divided into two types:1. PRIMARY RADAR2. SECONDRY RADAR

Primary radar or the simple radar locates a target by procedure described in section. But in cases as controlling of air traffic, the controller must be able to identify the aircraft and find whether it is a friend or foe. It is also desired to know the height of aircraft.

To give controller this information second radar called the secondary surveillance radar (SSR) is used. This works differently and need the help of the target aircraft it séance out a sequence of pulses to an electronic BLACK BOX called the TRANSPONDER, fitted on the aircraft. The transponder is connected to the aircrafts altimeter (the device which measures the planes altitude) to transmit back the coded message to the radar about its status and altitude. Military aircrafts uses a similar kind of radar system with secrete code to make sure that it is friend or foe, a hostile aircraft does not know what code to transmit back to the ground station for the corresponding receiver code.

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RADAR EQUATION

The amount of power Pr returning to the receiving antenna is given by the radar equation:

where

Pt = transmitter power Gt = gain of the transmitting antenna Ar = effective aperture (area) of the receiving antenna σ = radar cross section, or scattering coefficient, of the target F = pattern propagation factor Rt = distance from the transmitter to the target Rr = distance from the target to the receiver.

In the common case where the transmitter and the receiver are at the same location, Rt

= Rr and the term Rt2 Rr

2 can be replaced by R4, where R is the range. This yields:

This shows that the received power declines as the fourth power of the range, which means that the reflected power from distant targets is very, very small.

The equation above with F = 1 is a simplification for vacuum without interference. The propagation factor accounts for the effects of multipath and shadowing and depends on the details of the environment. In a real-world situation, pathloss effects should also be considered.

DIFFERENT TYPES OF RADARS

1. 3D Mobile Radar (PSM 33 Mk II)1. 3D Mobile Radar (PSM 33 Mk II)

3-D mobile radar employs monopulse technique for height estimation and using

electronic scanning for getting the desired radar coverage by managing the RF transmission

energy in elevation plane as per the operational requirements. It can be connected in air

defence radar network. The Radar is configured in three transport vehicles, viz., Antenna,

Transmitter cabin, Receiver and Processor Cabin. The radar has an autonomous display for

stand-alone operation.

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FEATURES

Frequency agility  

Monopulse processing for height estimation  

Adaptive sensitivity time control  

Jamming analysis indication, pulse compression, plot filtering / tracking data

remoting 

Comprehensive BITE facility 

2. Low Flying Detection Radar (INDRA II)2. Low Flying Detection Radar (INDRA II)

The low-level radar caters to the vital gap filling role in an air defence environment. It is a

transportable and self-contained system with easy mobility and deployment features. The

system consists mainly of an Antenna, Transmitter cabin and Display cabin mounted on three

separate vehicles.

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SYSTEM CHARACTERISTICS

Range up to 90 km (for fighter aircraft) 

Height coverage 35m to 3000m subject to Radar horizon 

Capability to handle 200 tracks 

Association of primary and secondary targets 

Automatic target data transmission to a digital modem/networking of radars 

Deployment time of about 60 minutes

FEATURES Fully coherent system  

Frequency agility  

Pulse compression  

Advanced signal processing using MTD and CFAR Techniques  

Track while scan for 2-D tracking  

3. Tactical Control Radar3. Tactical Control Radar

This is an early warning, alerting and cueing system, including weapon control

functions. It is specially designed to be highly mobile and easily transportable, by air as well

as on the ground. This radar minimizes mutual interference of tasks of both air defenders and

friendly air space users. This will result in an increased effectiveness of the combined combat

operations. The command and control capabilities of the RADAR in combination with an

effective ground based air Defence provide maximum operational effectiveness with a safe,

efficient and flexible use of the airspace.

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FEATURES All weather day and night capability  

40 km ranges, giving a large coverage  

Multiple target handling and engagement capability  

Local threat evaluation and engagement calculations assist the commander's

decision making process, and give effective local fire distribution  

Highly mobile system, to be used in all kinds of terrain, with short into and out of action

times (deployment/redeployment)

Clutter suppression  

RADAR APPLICATION

Air traffic control uses radar to track planes both on the ground and in the air, and

also to guide planes in for smooth landings.

Police use radar to detect the speed of passing motorists.

NASA uses radar to map the Earth and other planets, to track satellites and space

debris and to help with things like docking and maneuvering.

The military uses it to detect the enemy and to guide weapons.

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RADAR RADAR TRANSMITTERTRANSMITTER

The radar transmitter produces the short duration high-power of pulses of energy that

are radiated into space by the antenna. The radar transmitter is required to have the following

technical and operating characteristics:

The transmitter must have the ability to generate the required mean RF power and the

required peak power

The transmitter must have a suitable RF bandwidth.

The transmitter must have a high RF stability to meet signal processing requirements

The transmitter must be easily modulated to meet waveform design requirements.

The transmitter must be efficient, reliable and easy to maintain and the life expectancy

and cost of the output device must be acceptable.

The radar transmitter is designed around the selected output device and most of the

transmitter chapter is devoted to describing output devices therefore:

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Picture: transmitter of P-37

One main type of transmitters is the keyed-oscillator type. In this transmitter one

stage or tube, usually a magnetron, produces the rf pulse. The oscillator tube is keyed

by a high-power dc pulse of energy generated by a separate unit called the modulator.

This transmitting system is called POT (Power Oscillator Transmitter). Radar units

fitted with an POT are either non-coherent or pseudo-coherent. 

Power-Amplifier-Transmitters (PAT) are used in many recently developed radar sets.

In this system the transmitting pulse is caused with a small performance in a

waveform generator. It is taken to the necessary power with an amplifier flowingly

(Amplitron, klystron or Solid-State-Amplifier). Radar units fitted with an PAT are

fully coherent in the majority of cases.

o A special case of the PAT is the active antenna.

Even every antenna element

or every antenna-group is equipped with an own amplifier here.

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Electrical specifications:

1. Prime Power : 3 Phase, 415V 10% (line to line); 50 Hz2. Microwave Tube : TWT 3. Frequency range : 3.1 to 3.5 GHz4. Peak Power : 120 kW – 185kW at TWT output5. Average Power : 4.0 kW at 140kW peak 6. Pulse Width (RF) : 32 s (normal), 6 s & 64 s (selectable)8. Duty : 3.2% (max)

11. Protection : Crowbar protection to safeguard Tube and HVPSU

Modes of operation and control

The transmitter is designed to operate in the following modes defined as adequate controlled states.a) OFF : All subsystems switched OFFb) Cold Standby : Only LVPSU’s, TWT heater and Grid biases a r are switched ON. No High Voltage applied.c) Hot Stand By : High Voltages applied, No RF and No grid Pulsing.

d) Transmission : RF power delivered to Antenna / matched load.

Transmitter Control

a) Local : To control through control panel on the transmitter.b) Remote control : To control from the operator console through control interface.

Dimension & Weight

(a) Packaging : Three Racks With front, rear and side access. (b) Size : 1800(H) 1900(W) 800(D) (c) Weight : 1200 Kg (approximately).

BRIEF DESCRIPTION OF THE RADAR SUBSYSTEM

Main Circuit of Radar Subsystem

High Tension Unit

Transmitter Unit

Lo+Afc Unit

Receiver Unit

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Antenna

Video Processor

High Tension Unit -

The high tension unit converts the 115v 400Hz 3 Phase mains voltage into a d.c

supply voltage of about 4.2kv for the transmitter unit.

The exact value of the high voltage depends on the selected PRF(low,high or extra)to

Prevent the dissipation of the magnetron from becoming too high PRF the lower the supplied

high voltage

Transmitter Unit –

The transmitter unit Comprises

Submodulator

Modulator

Magnetron

Afc control Unit

The magnetron is a self – oscillating RF Power generator. It supplied by the

modulator with high voltage Pulses of about 20kvdc, whereupon it Produces X-band Pulses

with a duration of about 0.35us. The generated RF Pulses are applied to the receiver unit.

The Pulse repetition frequency of the magnetron pulses is determined by the

synchronizations circuit in the video Processor, Which applies start pulses to the sub

modulator of the transmitter unit. This sub modulator issues start Pulses of suitable amplitude

to trigger the thyraton in the modulator. Which is supplied by the high tension unit, Produces

high voltage Pulses of about 20kvDC.As a magnetron is self- oscillating some kind of

frequency control is required. The magnetron is provided with a tunning mechanism to adjust

the oscillating frequency b/w certain limits. This tunning mechanism is operated by an

electric motor being part of the Afc control circuit. Together with circuits in the Lo+Afc

units, a frequency control loop is created thus maintaining a frequency of the SSLO and the

magnetron output frequency.

LO+AFC Unit

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The Lo+Afc unit determines the frequency of the transmitted radar pulses. It comprises-

Lock Pulses mixer

Afc discriminator

Solid state local oscillator(SSLO)

Coherent oscillator(COHO)

The Afc lock Pulses are Pulses are also applied to the COHO. The COHO outputs

signals with a freq. of 30Hz, and it is synchronized with the pulse of each transmitter Pulse.

In this way a phase reference signal is obtained, required by the Phase sensitive detector in

the receiver unit.

Receiver unit

The Rx unit converts the received RF echo signal to IF level and detects the IF signals

in two different ways, two receiver channel are obtained, called MTI channel and linear

channel.

The RF signal received by the radar antenna pass the circulator and are applied to a low

noise amplifier. The image rejection mixer mixes the amplified signals with the SSLO

signals, to obtain a 30MHz IF signal is split into two branches.viz, an MTI channel and a

linear channel.via directional coupler, a fraction of the low noise amplifier output is branch

offer and applied to the broadband jamming detector. The BJD is a wideband device, which

amplifies and detects the signal applied. The resulting signal is passed on the SJI-STC circuit

(Search jamming indication sensitivity time control) in the video Processor , if jamming

occurs, it is used to prevent a polar diagram of a jamming on the PPI Screen, Which shows

the direction of the jamming source.

In the MTI channel, the IP signal is amplified again by the MTI main amplifier and

applied to the phase sensitive detector. The second signal applied to the phase sensitive

detector PSD is the phase reference signal from the COHO. The output signal of the PSD

consists of video pulse, the amplitudes of which are a function of the phase difference

between the two input signal of the PSD. The polarity of the video pulse indicate whether the

phase difference is positive or negative.

The phase differences between the corlo signal and if echo signals from a fixed target

are constant whereas those between the COHO signal and if echo signals from a moving

target are subject to change.

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The PSD output signal is applied to the canceller in the video processor.

The linear detector outputs positive video signals which are passed on to the colour

PPI drive unit.

Antenna

The antenna is a cosecant square parabolic reflector, rotating with a speed of about 48

r.p.m. in the focus of the reflector is a radiator, which emits the RF pulses from the circulartor

and which receives RF echo Pulses.

In the waveguide is Polarisation shifter, which causes the polarization of the RF

energy to the either horizontally or circularly. The polarization shifter is controlled by the

system operator.

Video Processor

The video processor processes the MTI receiver channel, to make the video suitable

for presentation on the colour PPI screen and for use by the video extractor.

The main circuit comprised by the video processor are :

Synchronization circuit.

Canceller

Floating level circuit

Correlator

Synchronization circuit

The synchronization circuit develops the start pulse for the sub modulator in the

transmitter unit, and accordingly it generates the timing pulses required by the canceller.

The repetition time of the start pulses depends on the PRF is staggered Pseudo-

randomly : 32 point stagger is used for low and high PRF and 64 point stagger is used for

extra PRF. The 64 point stagger for extra PRF is actually is compound of a 32 point staggered

short PRT and 32 point staggered long PRT and a 32 point staggered long PRT.

Canceller

The canceller is a circuit used to suppress the echo’s of fixed targets or very slow

moving targets. The canceller makes use of the difference in phase behavior moving and

fixed targets with moving target and phase differs from pulse to pulse, but with fixed targets

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the phase is constant (i.e. the PSD output is constant). The suppression by the canceller is

limited. The higher the PRF of the radar pulses, the better the suppression factor; a further

cancellation improvement can be obtained by using a triple canceller instead of a double

canceller; here a compromise is to found.

Main Control Assembly(MCA)

1.ON/OFF switch

(CHA)

2. PWR ON indicator (LED)

3. ON/OFF switch (CHB)

4. PWR ON indicator (LED)

5. S33 switch MASTER

CLEAR pushbutton

6. DS1 indicator (LED)

(indicates which CHANNEL

is operating

Purpose Of the Equipment:

• To amplify the RF power received from REC in the transmission band.

• To exchange serial data with the associated Receiver equipment to provide real time information about the operating status.

• To allow full equipment control / monitoring capabilities from a remote site.

• To provide modular composition of the high power amplifier stage so that to continue normal operation even with a section faulty.

• To allow corrective maintenance procedures in the high power amplifier stage without interrupting the normal operation (RF output power is reduced but it is not inhibited).

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Salient Features:

• Contains 8 HPA modules.

• The power supply circuit includes two power transformers which produce 21 Va.c. to supply the HPA modules and MCA.

• MCA consist of two identical processing channels (A and B); only one takes the equipment control ,other takes the "hot stand-by" role.

• Each HPA modules has its own self protected power supply section that provides a regulated voltage for the solid state power amplifiers and the BITE.

• In the event of a HPA failure the equipment continues to function using remaining amplifiers while maintenance can be performed on the faulty module.

EQUIPMENT ARCHITECTURE

Composed of seven main areas:

− Power Supply and Cooling System.

− RF Driving

− RF Power Amplification

− RF Power Monitoring

− Processing Logic

− Transmission Controller

− External Interfaces

Transmitter Turn-ON Mechanism:

• I/P main power supply is routed through breakers CB1 and CB2 located on AC Distribution Panel, to blower assys and T1 transformer.

• 21V-50Hz 3 phase output from T1 is applied to relay box.

• +28V PWR ON command from REC energizes relays K1 ÷ K6, distributing 3Ø 19V-50Hz and 21V-50 Hz voltages to the SPS Cards.

• TLRRON signal is activated, through MUX board causes the K1 closure and turns ON CB3 breaker.

• Voltage is applied to the primary winding of T2 power transformer which then provides the 21V-50Hz - three phase supply voltage to all the HPA modules of the equipment.

AUX PWRON signal sent to Radar Receiver confirming that the transmitter equipment is turned on when CB1 & CB2 ON.

High Power Amplifier(HPA):

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1. POW indicator (LED)

2. RAD indicator (LED)

3. LOP indicator (LED)

4. RF interlock

5. CANNON interlock

6. VSWR MONITOR (reflected output power)

7. RF MONITOR (output power)

8. RF MONITOR (input power)

9. V. MAIN (power supply voltage)

10. V. TEMP (test points used to find out internal

temperature)

HPA Description:

• Interlock CANNON( safety switch ),enables i/p supply if properly connected.

• RF Amplifier Stages Control:

- LIU activates the IRAD signal enabling the input of the RF signal into the amplification chain.

-LIU evaluates RF signal level in i/p and according to the current total absorption, the number of transistors belonging to the final stages which are faulty.

-HPA module can also operate with few final transistors operative.

-External Bus Management: Links HPAs to Transmission controlller & External Interface.

• HPA Bus is divided into two parts-

-Control Signals: BTRIG, EMCON,PSYN,XERAD

- RS-485 serial channel: CK,TXD.RXD

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CONCLUSION

Making this project was a huge learning experience for us. We have enjoyed building the project brick by brick, and it has given us the opportunity to come up with new innovative ideas and show talent. The Project was our first step into practicality of theory on large scale and an introduction into Industry and concept of Radar and Transmitter . It created very challenging situations for us, which involved a lot of mind boggling.

As we are not professionals we built this project according to our knowledge and skills, we tried our level best to make it as good as we can, but still it has a lot of scope of improvement. But its overall look and feel great and gives an exposure of Indutry and Professionalism .

REFERENCES

1.RADAR Engineering by G.S.N Raju,Raju.

2.Microwave and Radar Engineeering by V.S Bagad.

3.www.wikipedia.com

4.www.radartutorial.eu

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