A Ka-band Backward-Wave Oscillator with Grating Slow-Wave Structure Developed by a Simplified Approach

We have devised a timesaving procedure for developing a Ka-band backward-wave oscillator (BWO). We developed a fast 1D-PIC code in radiation simulation to predict the output power for slow-wave structures (SWS) of any design. In the experiment, we also developed an electron-beam transport system, which permits us to replace SWS without exposing the dispenser cathode to the air; thus, an efficient investigation for various kinds of SWSs has become possible. All the processes for developing the BWO were accomplished over several months. Herein, we demonstrate the proposed approach by developing a 40 GHz BWO with a grating SWS.