ABSTRACT
This chapter examines the telegrapher’s equation, which is the starting point for transmission line theory. It discusses enclosed waveguides including rectangular and circular waveguides. The chapter explores the concept of guided waves in simple Transverse electromagnetic (TEM)-guiding structures in terms of the simple model provided by Telegrapher’s Equations. TEM modes have both the electric and magnetic field transverse in the direction of propagation. The chapter describes the basic properties of planar transmission lines. A number of variations of the rectangular waveguide are available, including single and double-ridged waveguides, which are desirable because of increased bandwidth. Planar guiding structures are composed of a comparatively thin dielectric substrate with metallization on one or both planes. The simplest form of microstrip consists of a single conductor on a grounded dielectric slab. Microstrip is the most common type of planar transmission line used in microwave and millimeter-wave circuits, with a great deal of design data freely available.
