By James B. Grabenstein, Microdyne Corporation
With programming source availability changing, real estate restrictions and cost effectiveness in mind, the satellite communication industry has generated the requirement to obtain service from more than one satellite into the sane TVRO system. To achieve this goal, additional feeds have to be added to the existing TVRO system or the antenna changed to another type.
This paper is an attempt to outline some of the advantages and applications in changing to a multiple feed system on a parabolic antenna reflector. It covers some of the theory and math that has been incorporated into a computer program that is used to predict the gain and noise generated when the feed point is shifted from normal boresight. This paper will cover some of the data gathered from an extensive testing program that has been done on the multiple feed system in the field. The predicted data and field test data will be compared and analyzed.