An Accurate Measure Method of Loss Power for Space TWT

An accurate measuring method of loss power for RF circuit and collector for space TWT is proposed in this paper, which based on the measurement of energy distribution curve at entrance of collector. The method measures the energy distribution curve of collector inlet, the DC power of electron beam, the interception loss power, and the voltage and current of collector. By using the measured energy distribution curve of collector with 10% working ratio, the power in spent beams at entrance of collector can be obtained. Then according to the principle of energy conservation, the circuit loss and the heat loss of the collector can be calculated. A space TWT with a four-stage depressed collector is measured in this paper. Measurement results show that the circuit loss and heat loss of the collector are 1.25W and 45.16W, respectively.