B.E Fifth Semester Examination, Dec-10/Jan-11
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.
c. Calculate the resonant frequency of a rectangular resonator of dimensions a=3cm, b=2cm, d=4cm, when the mode of operations is TE101. (6 Marks)
3 a. With neat diagrams explain the construction and operation of READ diode.
b. Draw the equivalent circuit for parametric amplifier and explain.
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 106 cm/sec, determine (a) the drift time of the carriers (b) the nominal frequency of the IMPATT diode.
4 a. Give the relation of Z, Y and ABCD parameters with S-parameters.
b. Explain the Phase shift Properties. (4 Marks)
c. Explain the symmetrical Z and Y matrices for reciprocal network.
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.
b. Give a brief account of attenuation losses in parallel strip line.
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 10-11W. Determine the cross section of the target the Radar can sigh.
8 a. Explain the principle and working of MTI radar with the help of block diagram.
b. Write brief notes on-
i) Blind speed
ii) 3-pulse cancellor
iii) Applications of Radar (4x3=12 Marks)