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10000EC403122001

PART ‏تا‎

Answer any two full questions, each carries 15 marks.
Explain the amplification process of Travelling Wave Tubes (TWT) and define
its gain parameter.
Explain the constructional features of two-hole directional coupler and derive S
Matrix.
Explain how impedances are measured using slotted line and reflectometer.
Define a microwave junction. Deduce the scattering matrix relation between the
input and output of an n X n junction starting with an analogy of a transmission
line.
Show that the magnitude of the velocity fluctuation of the electron beam is
directly proportional to the magnitude of the axial electric field in a helix TWT.
Explain with figure a ferrite isolator can support only forward direction waves.

PART C

Answer any two full questions, each carries 20 marks.
Discuss the various limitations of microwave transistors. What are the main
assumptions made in power frequency limitations?
Explain with block diagram the principle of operation of a pulsed Radar.
Prove that decrease in drift velocity with increasing electric field can lead to the
formation of a high field domain for microwave generation and amplification.
Explain low noise front ends? Describe in detail the utility of low noise front
ends.
With neat diagram explain serial loading and parallel loading in tunnel diode.
How tunnel diode can be used as an oscillator?

Explain the operation of commonly used Radar displays.

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