Study of 12- and 21-GHz Dual-band Feed Horn for Reflector Antenna in Satellite Broadcasting Reception

The 12-GHz band (11.7 to 12.75 GHz) is used for satellite broadcasting of high-definition television (HDTV) and ultra-high-definition television (UHDTV) in Japan. The 21-GHz band (21.4 to 22.0 GHz) has also been allocated to satellite broadcasting in Europe, Africa, and Asia Pacific. The BSAT-4a satellite not only has 12-GHz-band transponders for UHDTV services, but also 21-GHz-band experimental transponders for future broadcasting services. To receive the services using these two frequency bands with a single antenna, we have studied a receiving antenna composed of an offset parabolic reflector and a 12- and 21-GHz dual-band horn antenna with a choke horn. In this study, we designed three types of feed horn and compared their applicability to the offset parabolic reflector antenna. We conducted link calculations to confirm the feasibility of the 12-and 21-GHz dual-band receiving antenna with the proposed feed horn.