A 500 Watt coupled-cavity TWT for Ka-band communication

Last year CPI reported the development of a 500 W PPM focused coupled-cavity TWT for conduction cooled amplifier systems which is to be introduced into the commercial satellite communication market. This paper is to update the community on technical progress regarding performance of the TWT in communication systems. Basically, the TWT is capable of greater than 500 MHz instantaneous bandwidth and is cathode voltage tunable from 28.3 to 30 GHz. The TWT may be operated saturated at the 500 W output power level or backed off from saturation in the linear mode. CPI's Satcom Division has integrated the TWT into a conduction cooled transmitter box suitable for antenna hub-mount applications. The amplifier uses pre-distortion networks to provide a high degree of linear response when operated in output power back-off mode.