The evolution of microwave and millimeter wave tubes

Microwave and millimeter wave tubes continue to be used in numerous modern and legacy electromagnetic systems because they are powerful, efficient, reliable and affordable. This paper will trace the evolution of travelling wave tubes (TWTs), klystrons, fast-wave, and other of these devices and identify new developments and research thrusts. Microwave power modules (MPMs) and millimeter wave power modules (MMPMs) integrate solid state amplifiers with TWTs to form compact, efficient, low-noise microwave and millimeter wave power amplifiers. Most of these modules include electronic power conditioners and many include linearizers, protective circuitry, and digital control. MPMs and MMPMs are vital modern system building blocks and the presentation will identify certain recent developments.