What is difference between Rectangular Waveguide and Circular Waveguide?

Answer 1

Rectangular waveguide and circular waveguide are metal hollow structure used to guide EM waves. Depending upon their shapes they are classified as rectangular or circular. They are basically a passive microwave device and acts like a High Pass Filter.

Rectangular waveguide :

It is the earliest kind of the transmission lines.

It supports supports TM and TE modes.

It does not support TEM waves because it has only one conductor and cannot define a unique voltage.

Conductor is filled with a material that has material with permittivity e and permeability m.

Cutoff wavelength equation for is define below.

λc = 2/

Here, m= number of half-wave along broad side dimension,

N= number of half-wave along the shorter side.

Circular Waveguide:

It maintains a uniform circular cross section along their length.

The cutoff frequency is unique for a specific waveguide mode that is assumed to be propagating in a waveguide of a given diameter and determines the lower frequency of the waveguide’s operating frequency range.

The cutoff frequency is calculated using the following formula:

Answer 2

circular is easy to manufacture than rectangular

As the name indicates the circular is circular in shape and rectangular is rectangular in shape

its uses same modes that is Te and Tm

I know this much only hope this helped u little bit atleast

A: In principle waveguides act as the equivalent of wires for high frequency circuits. For such applications, it is desired to operate waveguides with only one mode propagating inside of the waveguide. With rectangular waveguides, it is possible to design the waveguide such that the frequency band over which only one mode propagates is as high as 2:1 (i.e. the ratio of the upper band edge to lower band edge is 2). With circular waveguides, the highest possible band width allowing only a single mode to propagate is only 1.3601:1. I found it on Wikileaks.