SHF High-power TWT´s for earth stations

This paper describes the 14 and 30 GHz TWT´s which were designed specifically for the earth stations of the new experimental broadcasting satellite and communications satellite experiments. The coupled cavity type RF circuits of these tubes were severed into three sections and optimized to the requirements for their frequency coverage and efficiency. Each TWT has one stage depressed collector and is cooled by only one blower including the electro-magnet for beam focusing. The 14 GHz TWT can deliver more than 2 kW CW power output with 40 dB gain and the 30 GHz TWT can deliver more than 400 W CW power output with 36 dB gain. Group delay of 1 nS over the TV channel for the broadcasting experiment, and AM-PM conversion of 5 °/dB in the 30 GHz TWT are also measured.