Beam forming network for reconfigurable antenna of 21-GHz band broadcasting satellite

In this report, we introduced an array-fed imaging reflector antenna configuration for the engineering model of 21 GHz-band broadcasting satellite in Japan. The proposed reconfigurable reflector antenna can supply enough power for a 300 MHz class wide band transponder by combining the output power of each horn antenna as well as exploit the limited resources because of its ability to control radiation pattern in order to increase power locally in the area of severe fading. We fabricated and tested a prototype phase shifter and attenuator unit. The measured electrical performance was satisfied our requirements. And we confirmed the prototype PS/ATT unit had enough accuracy to configure radiation patterns covering over Japan.