Improved TWTs for electronic countermeasure application

Some efforts in the development of a multistage depressed collector (MSDC) are reviewed. The MSDC is to operate in an electronic countermeasure system (ECM) with minimum overall efficiency in the range 35 to 50%. The effects of interception, harmonic output, and skin effect losses on the design of high-efficiency tubes with a MSDC are briefly discussed. Future experimental work will attempt to put a multistage depressed collector on a 400-watt CW 4.8 to 9.6-GHz helix TWT. By using a unique valve assembly, different collector configurations can be tested while maintaining the circuit under vacuum. The work will determine the sensitivity of overall tube efficiency to the number of collector, length of the collector, aperture size, and plate angle.