Which one of the following can be used for amplification of microwave energy?

R = = 400?.

R must be at least 400? so that current in LED does not exceed 10 mA.

They are related.

It uses a single cavity resonator for generating microwave oscillations.

Its parts are electron gun, resonator, repeller and output coupling.

It operates on the principle of positive feed back.

The repeller electrode is at negative potential and sends the partially bunched electron beam back to resonator cavity.

This positive feedback supports oscillations. Its feature are:

1. Frequency range - 2 to 100 GHz

2. Power output - 10 MW to about 2 W

3. Efficiency - 10 - 20 %

Its applications include radar receivers, local oscillator in microwave devices, oscillator for microwave measurements in laboratories etc.

Z_C = Z_OC - Z_SC ⟹ 50 = (100 + j150)(Z_SC) .

Because capacitor charge is retained.

The circuit is a second order active low pass filter for which gain is 40 dB/decade.

In force voltage analogy force is analogous to voltage and velocity to current. Just as , force/velocity = mechanical impedance.

and . Since VSWR = ?, |r_v| = 1. This can happen if Z_L = 0 or Z_L = ?, i.e., line is o.c or s.c.