Study of Dual-Band Horn Antennas for Offset Parabolic Reflector Antenna in 12- and 21-GHz- Band Satellite Broadcasting Reception

The 12-GHz band (11.7 to 12.75 GHz) is used for satellite broadcasting of high-definition television and ultra- high-definition television in Japan. Moreover, the 21-GHz band (21.4 to 22.0 GHz) has been allocated to satellite broadcasting in Europe, Africa, and Asia Pacific. The BSAT-4a satellite has not only 12-GHz-band transponders but also 21-GHz-band 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 feed horn antenna. In this study, we designed two types of dual-band horn antenna and evaluated the performance of the reflector antenna configuration. Simulation results showed that an aperture efficiency of more than 70% was obtained in both bands.