Antennas and Wireless Communication Systems
Branislav M. Notaroš · 2017
Although any conductor with a rapidly time-varying current radiates electromagnetic energy into the surrounding space, some conductor configurations are specially designed to maximize electromagnetic radiation, in desired directions at given frequencies. Such systems of conductors, which sometimes also include dielectric parts, are called antennas. An arbitrary transmitting wire metallic antenna is represented as a chain of Hertzian dipoles. Wire dipole antennas of all possible lengths have at least one common zero in the radiation pattern. Often, people need to analyze antennas in the presence of conducting ground planes. Such a plane can be an approximation of the earth&s;s surface, of a metallic plate to which the antenna is attached or placed in parallel, or of a large conducting object in the vicinity of the antenna. In many situations, the ground conductor can be assumed to be perfectly flat, of infinite extent, and perfectly conducting (PEC), so that the analysis model with a PEC ground plane suffices.