8175-8215 MHz MILSATCOM Band for the GOES-R PDU Signal and the 8025-8400 MHz Band for the SD Downlink

A system in which both processed data uplink (PDU) and sensor data (SD) downlink coexist within the 8 GHz band is one of several alternatives being considered for the GOES-R frequency plan. The 8 GHz studies performed so far indicate that having both PDU and SD downlink within the 8175-8400 MHz band is achievable. In such a design, a number of issues must be addressed related to interference to and from other systems in the neighborhood of the GOES-R frequency bands. These issues are self-interference from SD downlink transmitter to PDU receivers on the satellite, hardware complexity such as filter design, and payload configuration, for example, use of a single antenna for both SD downlink and PDU receive on the satellite or two separate antennas. Among the interference issues, the important ones are PDU and SD downlink self- interference, SD downlink interference to the deep space network (DSN) at Goldstone, PDU to DISA, and DISA shipboard terminal interference to PDU. In this paper we give a brief overview of the GOES-R system, followed by a detailed discussion of the design issues. A reference design that satisfies the link performance, interference limits, and implementable hardware constraints is given in this paper.