Communication satellite antennas

During the previous two decades, communication satellites have developed from the pioneering Telstar to the highly sophisticated ATS-6. Concurrrently, the spacecraft antennas have developed from a low-gain "omnidirectional" antenna to the multifrequency multifunction antenna farm on ATS-6. Tomorrow\´s communication satellites will carry antennas whose radiation patterns can be changed to accommodate specific needs as they arise. In this paper, the general description and characteristics of several generic communications antennas are described as their development is traced from the early days of Telstar to a present day version of a multiple-beam antenna. The latter system is considered in considerable detail and with some reference to design techniques and measured performance.