94 GHz TWT for military radar applications

Summary form only given, as follows. For future military radar applications high frequency, light weight TWTs become more and more important. To cover this market, TTE (Thomson Tubes Electroniques) started the development of a 94 GHz TWT. The goal of this program was a TWT (double comb delay line structure) in the 94 GHz frequency range with an instantaneous bandwidth greater 500 MHz (tunable within 1 GHz) and an output peak power greater 200 W in the center of the band (150 W over the band) for a duty cycle of max. 10%. In a second mode (different operating point) the goal for the output power was more than 100 W peak over the band and a duty cycle of max. 20%. Further parameters were the delay line voltage below 22 kV, a grid voltage swing of max. 400 V and mass smaller 1300 grams. The technical base of this program was TTE´s experience in development and production of TWTs in the 30, 35 and 60 GHz frequency range. From there we started with the modification and adaptation of the standard technologies and TWT design, to be applicable for the special requirements in the 94 GHz range, concerning the small mechanical dimensions and allowed tolerances. The basic design and main test results of the 94 GHz TWT are the content of this paper.