A Dual Polarized Wide Band Feed Chain for FSS and BSS Satellite Services

The request for telecommunication satellites with mixed BSS (Broadcast Satellite Services) and FSS (Fixed Satellite Services) services had been continuously increasing in the recent past. In order to minimize the number of overall antennas on these spacecrafts it is often advantageous to combine both services into a single antenna. Key component of such a satellite antenna is the feed system. Beside the general demands like a suitable co-polar pattern, low return loss and polarization purity over the entire frequency band, the feed system has to offer increased RE power handling capabilities: Due to the growing number of channels, the RE power operated by the feed chain will considerably increase. This leads to stringent requirements on the linearity compared to state of the art systems in order to avoid the generation of passive intermodulation products (PIMP). Similarly, an increased multipaction threshold is mandatory. A special feature of the feed chain is the adaptable horn. The horn is divided into a generic input section and an adaptable output section. This adaptable section allows for tailoring the radiation performance according to project specific requirements without violating the qualification status of the generic part of the feed chain. EADS Astrium responds to the needs of the market with a development of a wide Ku band feed chain under ESA contract. This article summarizes the design, RE performance and a possible application of the Ku wide band (WBKU) feed chain.