Routeing and filtering in the ETS‐V transponder for mobile communication experiments

Abstract

The Japanese spacecraft ETS-V implemented an experimental mobile satellite communication system via a transponder called AMEX (aeronautical maritime experimental transponder). L-band was used for the mobile link and C-band for the feeder link. For the L-band two-beam system routeing and filtering were performed through 12 SAW filters and four switches in the IF part. The effective frequency allocation plan was obtained considering the features of the links used and the characteristics of SAW filters. The filtering to prevent EMC problems was also studied for AMEX, which handles high-and low-level signals simultaneously. AMEX shows good performance in orbit and is being used for a variety of mobile communication experiments by many organizations including the Communications Research Laboratory. KEY WORDS SAW filter Transponder Mobile satellite communications