Ka-Band Space TWTs For Satellite Transponders in Japanese Programs and Trend of Performance Improvement

摘要

Currently many satellite systems for advanced satellite-based communications are proposed at Ka-band. on-borad TWTs are key components in a transponder on the satellites because TWT's DC power and mass occupy most part in the transponder. For construction of cost-effective systems, performance improvements such as efficiency enhancement and mass reduction are strongly required. In Japan, Ka-band has been used for satellite communications since experimental phase at its beginning of 1970s. In the course up to date, NEC TWT's performance has been remarkably improved. Last year, a Ka-band 50W TWT was delivered for DRTS satellites that are scheduled to be launhed in 2000/2002. This TWT exhibits efficiency of 56