A Comprehensive Review of Travelling-Wave Tube Technology

摘要

A review of TWT technology is presented comparing selected aspects and design procedures relative to application. The general theory of operation of various types of TWT designs is discussed together with a review of principles of their construction and trade offs. The travelling-wave tube (TWT) was invented by R. Kompfner in 1943, and the principle of TWT amplification was demonstrated by him at Birmingham University in the same year. A small signal theory of this device was extensively developed by J.R. Pierce. The TWT has been constructed to operate at many wavelengths, ranging from one meter to one millimetre. It has found wide application primarily because at any given frequency or power level, it offers much more bandwidth than any of its competitors. The travelling-wave tube, though structurally simple, is a 'Constructred Complication'. Because of its structural simplicity, TWTs have been built to operate at frequencies as high as 50 GHz. Modern requirements for TWT amplifiers often call for very wide bandwidths combined with high power output. For any practical application and ideal TWT is seldom available as an 'off-the-shelf' item mainly because more than two dozen independent parameters are required in order to completely describe the tube.