Total marks: --
Total time: --
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

Solve any one question from Q.1(a,b,c) &Q.2(a,b,c)
1(a) Why waveguides are required at microwave frequencies? Explain the following parameters of waveguide.
i) Phase Velocity
ii) Guide wavelength
iii) Cut off frequency
7 M
1(b) Explain the Faraday's rotation principle? Explain in brief the working principle of an isolator.
7 M
1(c) Explain the properties of E plane Tee with the help of a neat diagram. Also state its Scattering matrix.
6 M

2(a) An air-filled reactangular waveguided of inside dimensions 7×3.5cm operates in the dominant TE mode.
i) Find the cut off frequency
ii) Determine the phase velocity of the wave in the guide at frequency of 3.5 GHz.
iii) Determine the guided wavelength at the same frequency.
7 M
2(b) Define with expressions the following parameters of directional coupler.
i) Coupling Factor
ii) Directivity
iii) Insertion loss
iv) Isolation
7 M
2(c) When is it necessary to carry out Micrwave Network Analysis?
6 M

Solve any one question from Q.3(a,b) &Q.4(a,b)
3(a) What are the high frequency limitations of transistor? Explain the techniques to minimize this along with the performance parameters of transistor at high frequency.
9 M
3(b) Explain in detail the construction, operation, advantages and applicaitons of TWT amplifier.
9 M

4(a) A two cavity Klystron amplifier has the following specifications:
Beam Voltage: V0=1000V
Beam Current: I0=25mA
Frequency: f=3 GHz
Gas spacing in either cavity: d=1 mm
Spacing between centers of cavities: L=4 cm
Effective shunt impedance excluding beam laoding: Rsh: 30kΩ
i) The input gap voltage to give maximum output voltage V2
ii) Find voltage gain, neglecting the beam loading in the output cavity.
iii) Find the efficiency of the amplifier, neglecting beam loading.
10 M
4(b) What are cross field devices? Explain the Cavity Magnetron with Hull cut off condition in detail.
8 M

Solve any one question from Q.5(a,b) &Q.6(a,b)
5(a) Explain the working principle, advantages and disadvantages of Tunnel Diode in detail.
8 M
5(b) Draw equivalent circuit of Vractor diode. Explain in detail its construction and operation.
8 M

6(a) Explain construction, working and applications of PIN diode in detail.
8 M
6(b) Write a short note on:
i) Microwave Transistor
ii) Schottky Barrier diode.
8 M

Solve any one question from Q.7(a,b) &Q.8(a,b)
7(a) Explain attenuation measurement technique in detail.
8 M
7(b) Enlist Methods of measuring the Q of cavity resonator. Explain one method in detail.
8 M

8(a) Write short note on:
i)Tunable detector
ii) Microwave Power Measurement
8 M
8(b) Explain any two methods of measuring Impedance of a terminating load in a microwave system.
8 M

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