ABSTRACT
In the broadest sense, all of electrical engineering deals with some sort of guided-wave system. Maxwell’s equations and Poynting’s theorem indicate that, even in an elementary low-frequency circuit, energy is stored and power is transferred, not by wires or circuit elements. In this chapter, the authors discuss a classical transmission line. They had in mind artificial structures made for the purpose of guiding waves, but there are naturally occurring cases of waveguides as well. The reader already knew the types of waveguides: the rectangular metallic waveguide, the circular coaxial waveguide and the two-wire transmission line. The most readily understood waveguide is perhaps the classical transmission line. This line is not really associated with any particular physical structure, but rather serves as an approximate model for a wide variety of waveguides met with in practice. The structures like this have application in distributed amplifiers, and in three-dimensional versions, as negative refraction elements.
