Satellite TWT-amplifiers using the microwave power module concept and radiation cooled collectors

Microwave Power Modules (MPM´s) try to make the best use of the high power and high efficiency capability of Travelling Wave Tubes (TWT´s) and of the low weight, high gain and excellent signal processing characteristics of the solid state MIC or MMIC Linearizer Front End (LFE) technology. The use of LFE´s with satellite TWT´s allows one to reduce the tube length and mass by about 30%, resulting in a short or STWT of only 30 dB gain. The mass of the new Ku-band LFE is only 35 g. It has 1.3 W dc power consumption, 20 dBm output power and about 20 dB gain. Compared to standard TWT´s, the third order intermodulation distance of the LFE/STWT was improved by about 10 dB in backoff and 2 dB in saturation. The LFE is built in hybrid MIC and MMIC technology. The STWT had 62% efficiency over a 1.8 GHz bandwidth in Ku-band. An extremely light weight Be-Cone radiation cooled collector for TWT´s on Direct Broadcasting Satellites (DBS) was developed for further cost savings.<>