Microwave & Radar Engg.

(EC-302, Dec-2005)

Note: Section A is compulsory. Attempt any four questions from Section-B

and any two from Section-C.

Section-A

1. a) List the range of microwave frequencies.

b) What is bunching in reflex blystrins?

c) What is a crossed electric magnetic field?

d) Explain transferred electron effect.

e) Define “Detection” of microwaves.

f) Where is “circulator” used?

g) List the four different modes of Microwave bipolar transistor.

h) What is the need for matched termination?

i) Explain “Blind speed”?

j) What are Doppler tracking systems?

Section-B

2. Describe the construction, working and applications of a magnetron.

3. A microwave tunnel diode has a negative resistance Rn and the resonant

circuit resistance Rt. Derive an equation for the gain of a microwave Tunnel

diode amplifier.

4. Describe the analysis of MW components using sparameter.

5. Compare the methods for microwave measurements.

6. Explain the operations of a RADAR with a block diagram.

Section-C

7. An O-type TWT operates at 2 GHz. The slow wave structure has a pitch

angle of 5.7°. Determine the propagation constant of the traveling wave in

the tube. It is assumed that the tube is lossless.

8. Describe the Doppler radars.

9. Write notes on:

(a) Scanning techniques

(b) Advance transit time effect

Microwave & Radar Engg.

(EC-302, Dec-2007)

Note: Section A is compulsory. Attempt any four questions from Section-B

and any two from Section-C.

Section-A

1. a) List the limitations of vacuum tubes.

b) What is Gyrator?

c) What is the need of slow wave structure in TWT?

d) What is matched termination?

e) What are the applications of BWO?

f) An IMPATT diode has a pulsed operation voltage of 100V and a pulsed

operating current of 0.9A. The efficiency is about 10%. Calculate (i) the

output power and (ii) duty cycle, if the pulse width is 0.01ns and the

frequency is 16GHz.

g) What is multiple time around echoes?

h) What is Radomes?

i) How one can distinguish a stationary target and a moving target?

j) Mention advantages and disadvantages of phased array radar?

Section-B

2. How does magnetron work as an oscillator? Discuss.

3. Discuss the applications of PIN diode.

4. Derive the equation given below for directional coupler & then give its S-

matrix

p2

+ q2

= 1.

5. Draw the block diagram for measurement of Doppler direction using

synchronous motor and discuss how it indicates the direction of the target.

6. Discuss the radar frequencies & its applications.

Section-C

7. Discuss the methods for measurement of SWR.

8. What is angle tracking system, discuss its various techniques.

9. Write short notes on:

(a) Isolator & Circulator

(b) TRAPATT diode

Roll No. ...................... Total No. of Questions : 09] [Total No. of Pages : 01

B.Tech. (Sem. – 6th

)

MICROWAVE & RADAR ENGINEERING

SUBJECT CODE : EC – 302

Paper ID : [A0317]

Time : 03 Hours Maximum Marks : 60

Instruction to Candidates:

1) Section - A is Compulsory.

2) Attempt any Four questions from Section-B.

3) Attempt any Two questions from Section-C.

Section - A

Q1) (10 × 2 = 20) a) What is blind speed?

b) What do you understand by maximum unambiguous range?

c) What is scattering matrix? Give its properties.

d) What is velocity modulation?

e) What is the advantage of matched termination?

f) Explain how negative resistance can be used to obtain amplification?

g) Give classification of microwave tubes.

h) Define Quality factor, Q.

i) Give various applications of radar.

j) Why lumped circuit theory is not applicable at microwave

frequencies?

Section – B (4 × 5 = 20)

Q2) Explain lobe switching method of angle tracking in a radar.

Q3) Explain „pi‟ mode of operation in a magnetron.

Q4) What is a directional coupler? Explain various parameters of directional

coupler.

Q5) Describe Bolometer method for microwave power measurement.

Q6) For a radar, peak transmitted power is 2 MW, pulse size is 1 microsecond,

and pulse repetition frequency is 100 KHz. Calculate Average transmitted

power and unambiguous range.

Section – C (2 × 10 = 20)

Q7) a) Draw the block diagram of CW radar and explain its working.

b) Give comparison between MTI radar and Pulse Doppler radar.

Q8) What are the limitations of conventional solid state devices at microwave

frequency? Explain PIN diode.

Q9) Explain the working of Two-cavity klystron amplifier with suitable

diagrams.

J - 1237 1

Roll No. .... ............. Total No. of Pages : 02

Total No. of Questions : 09

B.Tech. (ECE) (Sem.–6th) MICROWAVE AND

RADAR ENGINEERING Subject Code : EC-

302

Paper ID : [A0317]

Time : 3 Hrs. Max. Marks : 60

INSTRUCTION TO CANDIDATES :

1 . SECTION-A is COMPULSORY.

2 . Attempt any FOUR questions from SECTION-B.

3 . Attempt any TWO questions from SECTION-C.

SECTION-A (10 × 2 = 20 Marks)

l. Write short notes on :

(a) List two discriminations between conventional tube and microwave

tube.

(b) What are stubs? Explain there applications in microwave.

(c) What are ferrites? Why these are useful in Microwave?

(d) Explain the negative resistance. How it is utilized in Varactor Diode?

(e) What are the applications of RADAR?

(f) Draw the block diagram of Basic RADAR.

(g) Explain the principle of phase shifter?

(h) What is function of delay line canceller?

(i) Why is hybrid Tee also called magic Tee?

(j) Mention the frequencies used for radar applications.

SECTION-B (4 × 5 = 20 Marks)

2 . What is transient time? Explain which is the best suitable transient time in

case of Reflex klystron & how it is calculated?

3 . Explain the construction, operation, working of reflex Klystron. Give its

typical characteristics also.

[A-12]-20

19

4 . What are cross field devices? How does a Magnetron sustain its oscillations

using the cross field principle? Assume the Pie-Mode for explaining the

same.

5 . Derive the scattering matrix relation between the input and output of a

N*N junction starting, with an analogy of transmission line junction.

6 . Drive the expression for RADAR Range.

SECTION-C (2 × 10 = 20 Marks)

7 . Compare typical features of the TWT and multicavity Klystron, highlighting

their similarities and dissimilarities.

8 . (a) Explain the construction, working & application of Circulator.

(b) Explain MTI RADAR with neat diagram.

9 . Explain in detail track with scan.

[A-12]