Antenna technology for frequency reuse satellite communications

In the past few years, the capacity of communications satellite systems has become limited by the available bandwidth. One method of overcoming this limitation is to reuse the bandwidth by employing spatially isolated antenna beams and/or orthogonal polarizations. This paper surveys the required antenna technology. The multiple-beam spacecraft antenna problem is addressed, and the curreent design status is summarized. The earth terminal antenna for a dual-polarized system is discussed along with polarization measurement techniques. Finally, circuits for compensating the depolarization resulting from precipitation on the propagation path are presented.