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All Q&A
1

What are cross field device? What role does the dc magnetic field play in their normal operation?

25 September, 2022
The cavity magnetron is a cross field device. Here the electric field between anode and cathode is radial whereas the magnetic field produced by a permanent magnet is axial.
2

What do you mean by cut off frequency of a waveguide? On what factor does the cut off frequency of a waveguide depend? Derive expression in support it.

25 September, 2022
Several modes of electromagnetic waves, corresponding to the solution of the Maxwell’s equations, propagate inside a waveguide. A given waveguide has a definite cut-off frequency for each allowed mode.
3

What is strip line?

25 September, 2022
Strip lines are essentially modifications of the two wire lines and coaxial line. These are basically planar transmission lines that are widely used at frequency from 100 MHz to 100 GHz.
4

What is microstrip line? What are the advantages and disadvantages of microstrip line? Show the electric and magnetic field lines of microstrip line explain the working principle of a microstrip antenna.

25 September, 2022
Microstrip line is an unsymmetrical strip line that is nothing but a parallel plate transmission line having dielectric substrate, the one face of which is metalized ground and the other face has a thin conducting strip of certain with 'w' and thickness 't'.
5

Define the quality factor. On what factors does the cut-off frequency of a rectangular waveguide depend? Derive expressions in support of your answer.

25 September, 2022
The quality factor (Q) of any resonant or anti resonant circuit is a measure of frequency selectivity and it defined by the equation
6

Write short note on Microwave Power Measurement

25 September, 2022
Microwave power measurement devices can be divided into two categories: devices such as detector , bolometer and thermocouples, whose resistance changes with the applied power and calorimeters in which the temperature rise of a known quantity of liquid being used as a load measured.
7

Write short notes on

  • Cavity Resonator
  • Hybrid Ring
25 September, 2022
At microwave frequency, the value of L and C will be so small that they cannot be practically realizable. At microwave the cavity resonator the cavity resonator can generate oscillation like L.C tuned circuit. When a short is placed across the waveguide, the wave reflected by the short, forms a standing wave along with the incident wave.