Development of a wide-band modem for a 21-GHz band satellite broadcasting system

A next-generation satellite broadcasting system using the 21-GHz band (21.4–22.2 GHz) allocated for satellite broadcasting is expected to provide large-capacity advanced broadcasting services. To use the 21-GHz band, higher output power to compensate for rain attenuation and protection of the radio astronomy band are required. We report the design and prototype of a 300-MHz class wide-band modulator-demodulator (modem) for use with the 21-GHz band satellite broadcasting system. The prototype modem is evaluated for signal characteristics and transmission performance with intermediate frequency connection.