Broadband frequency tuning in a gigawatt S-band relativistic BWO

Frequency tuning capability was studied for two varieties of pulsed gigawatt relativistic backward- wave oscillator (BWO): the resonant BWO and the BWO with increased cross- section having a resonant reflector. The tuning assumed adjustment of the tube's electrodynamics only, with no variation of electron beam parameters. The studies demonstrated that frequency tuning of as wide as 10–20% is achievable, depending on the tube's design peculiarities.