COMETS for Ka-band and millimeter-wave advanced mobile satellite communications and 21 GHz advanced satellite broadcasting experiments

COMETS (Communications and Broadcasting Engineering Test Satellite), which was developed to evaluate Ka-band (31/21 GHz) and millimeter-wave (47/44 GHz) advanced mobile satellite communications and 21-GHz advanced satellite broadcasting systems, is presented as well as the developed ground terminals. COMETS carries an SCPC/TDM regenerative transponder for direct mobile-to-mobile communications, and IF-filterbanks for interconnection between multibeams. For mobile and personal applications, a portable terminal for regenerative transponder experiments, and several antennas such as an active phased array antenna, a waveguide slot array antenna, and a torus reflector antenna were developed. For satellite broadcasting experiments, trellis-coded modems for HDTV transmission at 60/140 Mbps and 155 Mbps were developed.