B.TECH - Semester 7 microwave and radar engineering Question Paper 2013 (dec)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- Define velocity modulation.
- Define bunching.
- What is called reentrant cavity?
- Give the comparison between TWTA and klystron amplifier.
- What is the need of slow wave structures?
- State the floquet's periodicity theorem.
- Write the advantages of unipolar over bipolar transistor.
- What are the various modes of operation of Gunn diode?
- What is MTI radar?
- Define pulse Doppler radar. Answer any one full quesiion from each module. Each carries 20 marks.
- (a) Derive the power output for two cavity and multi cavity klystron amplifier. 10
- (b) A four cavity klystron VA-828 has the following parameters: Beam voltage, $\mathrm{V}_{0}=14.5 \mathrm{kV}$ Beam current, $\mathrm{l}_{0}=1.4 \mathrm{~A}$ Operating frequency, $\mathrm{f}=10 \mathrm{GHz}$ DC electron charge density, $\rho_{0}=10...
- (i) The dc electron velocity (ii) The dc phase constant (iii) The plasma frequency (iv) The reduced plasma frequency for $\mathrm{R}=0.4$.
- (v) The do beam current density. (vi) The instantaneous beam current density. OR
- Explain klystron oscillator. Derive an expression of power output and efficiency of the same. 20
- (a) (i) Drive the S-matrix for directional coupler. (ii) Explain about hybrid circuit. State its applications. ( $\mathbf{2} \times \mathbf{5}=\mathbf{1 0}$ marks)
- (b) A helix travelling wave tube operates at 40 Hz under a beam voltage 19 kV and beam current 500 mA . If the helix impedance is $25 \Omega$ and the interaction length is 20 cm , find the output power gain in dB . OR 2
- (a) Explain the construction and working of cylindrical magnetron.
- (b) Explain the construction working and application of isolator based on faraday rotation.
- (a) Explain the operation of microwave bipolar transistor with neat diagram. 10
- (b) Explain the principle of microwave tunnel diodes. OR
- (a) Explain in detail about Gunn diode with neat diagram.
- (b) Explain VSWR measurement.
- (a) Derive the radar range equation? Explain the factors that affect the maximum range of a radar?
- (b) How do you distinguish stationary target and moving target? Explain the working principle of MTI radar with neat block diagram. OR
- (a) Explain the working of
- (i) CW Doppler radar (ii) FMCW doppler radar
- (b) Discuss the navigation using loop antenna.