ABSTRACT
This chapter presents outdoor and indoor base station antenna systems, which are commercially used for the Japanese cellular system and the personal handy phone system. The antenna system consists of an antenna element, a feeding network, a phase control unit, and a diplexer or a duplexer. The main components of a base station antenna are an antenna element, a feed circuit network, and a phase shifter. A printed dipole antenna is the most popular element for the base station antennas of the cellular system, because a half wavelength dipole antenna has a wide-frequency bandwidth more than 15% for the input voltage standing wave ratio less than 2. The printed dipole antenna is mounted on a reflector to obtain a sector beam in the horizontal plane. The vertical polarization is mainly used for the cellular system; however, the horizontal polarization and ± 45° slant polarization are often used for the polarization diversity system.
