Antenna Systems for Cellular Base Stations

Base station antenna systems have undergone a dramatic development within the last decades: in the early days of cellular communications, the cells where more or less of similar size and circular shape, having a base station in the center. This base station typically was equipped with a passive omnidirectional antenna illuminating the whole cell. Since then, the cell topology has become more and more diverse, using different cell sizes and also cell sectorization of higher orders. Moreover, the increasing demand on dynamic control and adaptation of the cell size and of the cell capacity results in complex requirements for both the antenna structure and the transceiver system. Therefore, it makes sense to consider the base station antenna system as a whole, comprising the antenna radiators, the transceiver system, and the data preprocessing.

This system design approach is the basic idea of this chapter: it starts with basic antenna considerations, then different system topologies are described including their functionality and their development over the years, and finally, an outlook into future challenges and design aspects is given.