The first three papers of Session 22 were about the microwave power module (MPM). Only two of these papers were actually presented. The first paper was presented by R.F. Watkins of Northrup Grummens on Higher Power, Low Cost Mini TWT’s. With only small changes to the gun and collector, the "new mini TWT" has been upgraded 2 to 3 dB, to provide between 150 to 270 watts from 6 to 18 GHz. J. Tucek from Northrop Grumman was to present a paper on the Millimeter Vacuum Power Booster Development, but it was withdrawn. The MMPM was to operate over the frequency band 18 to 40 GHz. The development tube provides 100 watts from 18 to 35 GHz, however, the power fell off rapidly above 35 GHz requiring a redesign of the tube. J. Kennedy from Northrop Grumman presented a paper titled Low Voltage Power Booster TWT. This paper described a Ka-Band Prototype, which produces 18 watts minimum and 80 watts maximum across the frequency band 24 to 40 GHz. Redesign will be necessary to center over the 18 to 40 GHz band.

D. R. Whaley from Northrop Grumman presented a paper on High Perveance TWT Modeling and Experimental Verification. A modified version of CHRISTINE3D was implemented with a self-consistent Poisson solution. The computer simulated results of this highly scalloping, high perveance (10 mP) annular electron beam were very in close agreement to actual experimental data. T. Machida from NEC Electron Devices presented a paper entitled Development of Ka-Band 250 Watt Peak Power Helix TWT. The data on a TWT 27.5 to 30 GHz TWT providing 150 watts average and 250 watts peak was presented. This tube achieved 48% efficiency at 30 GHz. R. Dionisio from Alelco SPA Microwave Tubes submitted a paper entitled High Power X-Band Helix TWT for Airborne Radar Applications, which was not presented since the authors were not able to participate in the conference. The paper involved an 8 kW helix tube operating over the frequency 7.5 to 10 GHz at a duty of 5% with a shadow gridded gun attached directly to the cathode and an electronic efficiency of 25%.