**B.E Fifth Semester Examination, Dec-10/Jan-11**

**Model Set-2**

Microwave and Radar

1 a. Define and derive expressions for attenuation and phase constant, wavelength and velocity of propagation in a transmission line. (8 Marks)

b. Discuss applications and properties of smith chart. (5 Marks)

c. In a smith chart, plot the following impedances

i) 0.4-j3.8 ii) 1.6+j2.4 iii) 2.4-j0.75 (7 Marks)

2 a. Draw a neat diagram of a H-plane Tee junction and explain its operation. Write its [S] matrix. (8 Marks)

b. With a neat diagram explain the operation of a 3-port circulator.

(6 Marks)

c. Calculate the resonant frequency of a rectangular resonator of dimensions a=3cm, b=2cm, d=4cm, when the mode of operations is TE

_{101}. (6 Marks)3 a. With neat diagrams explain the construction and operation of READ diode.

(8 Marks)

b. Draw the equivalent circuit for parametric amplifier and explain.

(5 Marks)

c. An IMPATT diode has a drift length of 2.5µm. If the basic semi-conductor material is Silicon for which the drift velocity is 5 x 10

^{6}cm/sec, determine (a) the drift time of the carriers (b) the nominal frequency of the IMPATT diode. (7 Marks)

4 a. Give the relation of Z, Y and ABCD parameters with S-parameters.

(8 Marks)

b. Explain the Phase shift Properties. (4 Marks)

c. Explain the symmetrical Z and Y matrices for reciprocal network.

(8 Marks)

5 a. Explain with neat diagram the construction and operation of a precision rotatory phase shifter. (8 Marks)

b. Explain with neat sketches the construction and operation of a Magic Tee junction. List the characteristics and hence derive the s-matrix of a Magic Tee junction. (12 Marks)

6 a. With a neat diagram explain the construction and operation of a microstrip line.

(8 marks)

b. Give a brief account of attenuation losses in parallel strip line.

(8 marks)

c. Explain the advantages and disadvantages of Plannar transmission lines over Co-axial line. (4 marks)

7 a. Briefly discuss the origins of Radar. (8 Marks)

b. With a neat block diagram explain the operation of a Radar. (7 Marks)

c. A marine Radar operating at 10GHz as a maximum range of 50KM with an antenna gain of 4000. a transmitter as a power of 250KW and minimum detectable signal of 10

^{-11}W. Determine the cross section of the target the Radar can sigh. (5 Marks)

8 a. Explain the principle and working of MTI radar with the help of block diagram.

(8 Marks)

b. Write brief notes on-

i) Blind speed

ii) 3-pulse cancellor

iii) Applications of Radar (4x3=12 Marks)

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