ABSTRACT
This chapter provides an overview of fixed and mobile antennas for satellite communications. Since 1945, with the introduction by Arthur C. Clarke of the concept of an artificial satellite, antennas have played a significant role in the development of satellite communications. One inconvenience associated with the use of the geostationary orbit is its large distance from the ground, which requires powerful rockets to raise the satellite to this position. Another problem is the delay of the communication signal that has to travel a large distance. To establish the satellite communication link between a ground user and a satellite only selected frequencies can be used. Onboard the satellite, antennas are a part of the satellite communications payload module. Their location depends on the type of satellite. In the spin-stabilized type of satellite, the antenna module is positioned in the upper part of the spinning cylinder. One of the major requirements of an earth station is high directive gain.
