Question

TE and TM Modes in rectangular waveguides and define the parameters of rectangular waveguides.

Answer 1

TE MODE (Transverse Electric):

This waveguide mode is dependent upon the transverse electric waves, also sometimes called H waves, characterised by the fact that the electric vector (E) being always perpendicular to the direction of propagation.

TM mode (Transverse Magnetic):

Transverse magnetic waves, also called E waves are characterised by the fact that the magnetic vector (H vector) is always perpendicular to the direction of propagation

PARAMETERS OF A WAVEGUIDE:

1)Wave Impedance:   It is defined as the ratio of transverse electric field to that of the transverse magnetic field during wave propagation at any point inside the waveguide. It is also known as characteristic impedance.It is denoted by Zg.

2)cutoff wavelength: It the maximum signal wavelength of the transmitted signal that can be propagated within the waveguide without any attenuation. This means up to cut-off wavelength, a microwave signal can be easily transmitted through the waveguide. It is denoted by λc.

3)phase velocity: It is the velocity with which the transmitted wave changes its phase during propagation. it is basically the velocity of a particular phase of the propagating wave. It is denoted by Vp.

4)Group velocity:

Group velocity is the velocity with which wave propagates inside the waveguide. If the transmitted carrier is modulated, then the velocity of the modulation envelope is somewhat less as compared to the carrier signal.This velocity of the envelope is termed as group velocity. It is represented by Vg.

I hope the answer is clear. Thank you.