Rectangular Waveguide - TE10; (TM11 in case of TM waves)

Circular Waveguide - TE11;

Circular waveguides offer implementation advantages over rectangular waveguide in Calculations for circular waveguide requires the application of Bessel.

A waveguide, is a hollow rectangular tube, designed to channel microwaves from the Magnetron to the outside world.

Rather than use a wire, this is found to be the best way to transfer microwaves at 3 cm to 10cm wavelength. (Some 10cm systems use large coax instead)

They are normally found on radar systems, to transfer the signal to and from the rotating scanner to the transceiver unit.

Modern radars keep the length of the waveguide to a minimum, by housing the transceiver in the motor unit of the scanner, instead of a separate room.

Moisture in the air in a waveguide can scatter the microwave energy the waveguide is designed to transport. This translates into signal loss or attenuation. The VSWR drops, and that is not a good thing.

• waveguide is a metal pipe that contains and guides microwaves from place to place in a microwave system (e.g. oscillators, amplifiers, mixers, modulators, filters, antennas)
• horn antenna has a waveguide connected at its focus, in transmit mode the waveguide feeds the horn which then emits a microwave beam, in receive mode the horn collects a microwave beam and concentrates it int the waveguide