A periodically focused kilowatt level traveling-wave tube amplifier

A pulsed, kilowatt-level, S-band, traveling-wave tube amplifier is described which utilizes a periodic permanent magnet focusing system. A considerable saving in weight as well as the elimination of the magnet power supply is thereby achieved. The final packaged tube weighs less than ten pounds. A kilowatt level tube has previously been reported by Caldwell and Iversen. However, in order to incorporate periodic focusing into such a tube, an extensive redesign was necessary. A converging type electron gun is used; coupled helix transducers with a coupled-helix attenuator have been developed for use with the new focusing system. In addition to providing a compatible structure for use with a periodic focusing system, these changes have resulted in improved performance, particularly a wider bandwidth.