The need for a new generation of antennas

The antenna represents 40 to 50 percent of a satellite earth station, yet its technology has lagged behind that of other communications equipment. New technological changes should be considered or provided for in designing new antenna products. The antenna should be capable of simultaneous reception from multiple satellites in multiple frequency bands. Two such multibeam antenna configurations are the spherical reflector and the Torus antenna. Satellites should operate at both 4/6 and 12/14 GHz, demanding improved integrity of the reflector and mount. A 3 deg satellite arc separation is being considered, increasing the need for improved antenna sidelobe performance. Frequency coordination insures that the earth terminal will operate within acceptable interference limits of the system and protects it from future interference sources. The satellite arc will be extended 55 deg to 143 deg west, which will require additional azimuth coverage from an earth station antenna capable of viewing satellites across the arc. Bandwidth conservation will be achieved through frequency reuse, dual-band satellites, and special formatting and processing techniques.