ABSTRACT
Propagation is possible in modes in which one field has a component parallel to that direction, and such modes are important in that they may convey energy through hollow tubes of conducting material. Electromagnetic waves may be transmitted through hollow rectangular metallic waveguides in field configurations in which either the magnetic field or the electric field has a longitudinal component. Each distinct configuration is known as a mode and is characterized by a cutoff frequency below which it cannot exist as a traveling wave. This chapter explores traveling-wave mode for the waveguide with a rectangular cross section. The number of possible modes is classified as transverse electric (TE) or transverse magnetic (TM). In TE mode the electric field is confined to planes perpendicular to the waveguide axis, but a longitudinal component of magnetic field is necessary. In TM mode the magnetic field is confined to planes perpendicular to the waveguide axis, but a longitudinal component of electric field is present.
