Introduction

This Report addresses technical and performance issues associated with the design of multiple-feed BSS receiving earth station antennas.

The cost of the earth-segment of a BSS system depends on the ability to deploy receiving earth stations with antennas that are relatively small in size and low in cost to the consumer. The benefit of multiple-feed receiving earth stations is that they permit BSS customers to receive services from multiple satellite locations using one antenna, i.e. more programming with a single receiving earth station antenna. From the standpoint of a BSS satellite operator, the multiple-feed antennas allow more efficient use of the spectrum since they avoid the need to transmit the same programming from more than one orbital location. These benefits to both the consumer and the service provider would not be available in the case where only single-feed antennas are deployed.

However, unlike the use of single-feed antennas that typically results in a single beam with an easily predictable symmetrical antenna pattern1, the use of multiple-feed antennas, involving feeds not at the boresight of the reflector, results in antenna patterns that are broader and highly asymmetrical.

Section 2 of this Report addresses the technical considerations that should be taken into account in the design and deployment of multiple-feed receiving earth station antennas and satellite networks employing such earth station antennas. Section 3 provides descriptions and performance data of typical multiple-feed receiving BSS receiving earth station antennas currently in use.