New Sidelobe Envelopes for Small Aperture Earth Stations

The advent of domestic satellite systems and technological improvements in both space and ground equipment makes the use of small aperture earth stations economically feasible and attractive for broadcast satellite applications. With increasing use of the orbit spectrum, there is some concern that broadcast satellite systems may not be able to obtain satisfactory allocations of this orbit-spectrum resource because of interference considerations. Specifilcally, interference calculations based on the present envelope of 9 + 20 log (¿/¿0) result in comparatively large orbit spacings for broadcast satellites. Theoretical and experimental investigations of simple sidelobe suppression techniques, plus an analysis of experimental data on small aperture antennas (from data over a range of 40 < D/¿X < 100), indicate that much better sidelobe performance can be obtained with a very small cost or performance penalty.