Development results of Ka-band multibeam active phased array antenna for gigabit satellite

The high data rate and global satellite communication systems are expected to be an important agenda to the social and economic activities in the 21(st) century. Gigabit Satellite, an experimental Ka-band satellite communication system aims to achieve the real Global Information Infrastructure which provide the full range connectivity all over the world. In this communication payload, a Ka-band scanning spot beam antenna (SSBA) is required to realize high EIRP and G/T, for multiple international service areas. An active phased array antenna (APAA) which has been applied to the SSBA realizes flexible multiple beam forming as one of the most important and challenging technologies in this program. An APAA have been developed mainly for radar systems for many years. As for the satellite communication, the APAA have been developed by Communications Research Laboratory (CRL), National Space Development Agency (NASDA) and Mitsubishi Electric Corporation (MELCO), especially for S-band launched in 1987 as the engineering test satellite-6. This paper describes the design of the Ka-band APAA for Gigabit Satellite and the development results of the bread board model of Ka-band APAA with four multiple beams which consists of 64 radiating elements for both transmitting and receiving.