Design of a base station antenna with a sharp roll-off sector pattern

In the design of base station antennas for cellular architectures such as PCS, it is desired that the elevation and/or azimuth patterns be shaped to have a sharp sector pattern in order to maximize the gain and reduce interference. While the antenna analysis problem is one of determining the radiation pattern and impedance of a given antenna, the antenna synthesis or design is the determination of the characteristics of a specific antenna and its excitation to produce or acceptably approximate the desired pattern and/or impedance. There are basically two categories of pattern synthesis: sector or shaped beam patterns, and low side-lobe, narrow beam patterns. The focus of this paper is on the former type. Only linear arrays are considered.