Intelsat III traveling wave tube power supply

The performance requirements and design approach used to develop the Intelsat III dual TWT power supply are discussed. In addition, final acceptance test performance data are examined. The dual TWT power supply described here provides power regulation and certain control functions for a 0.1 watt (R.F.) driver and a 12 watt (R.F.) power amplifier operating at 4 GHz. The supply operates from a spacecraft bus voltage of 22 to 31 volts and delivers nearly 2 KV to the high power TWT. Switching regulators are used so power dissipation remains low and virtually constant over the entire input voltage range. The supply is encapsulated and weighs 4.0 lbs. in its 10.6" x 2.3" x 3.5" aluminum case.