Electromagnetic Field Theory - Engineering

Q1:

The attenuation in a waveguide near the cut off frequency is

A zero

B low

C high

D very high

ANS:B - low

It will be very high because at the cutoff the gain factor will not be a flat band which will become flat as we move away from the cutoff because we know the waveguide is a high pass filter. So as we move away from the cutoff then we are going towards saturated gain a flat line parallel to x-axis.