Study of a terahertz folded waveguide oscillator with sheet electron beam

High power vacuum electronic devices of the millimeter wave to terahertz regime are attracting extensive interest due to their potential applications in science and technologies. In this paper, a novel sheet beam (SB) folded waveguide (FWG) slow-wave structure (SWS) is applied and studied for enhanced output power of oscillators. Through the analysis of high-frequency characteristics of the SB FWG-SWS, the selection of an appropriate beam-wave interaction point on the dispersion curve and beam position is determined for an SB folded waveguide oscillator (FWO) operating near the 2 pi stopband point. The fundamental mode operation of the SB FWO was verified by the particle-in-cell simulation results, which also indicate that the SB FWO exhibits a better outstanding performance (84.6 W with a beam voltage and current of 25.1 kV and 200 mA, respectively) than the conventional circular beam FWO. The transmission stability of the SB was analyzed by observing the interception beam current in the FWO. The voltage and frequency tuning performance of the SB FWO were discussed in combination with clutter suppression. A preliminary experiment was conducted by fabricating a 220 GHz SB FWG-SWS and measuring the S parameter.

Automated summary

This paper presents a novel sheet beam folded waveguide slow-wave structure for enhanced output power of oscillators in the millimeter wave to terahertz regime. Through particle-in-cell simulation results, it is demonstrated that the SB FWO exhibits better performance than conventional circular beam FWO. The voltage and frequency tuning performance of the SB FWO, as well as clutter suppression, were discussed, and a preliminary experiment was conducted to measure the S parameter of a 220 GHz SB FWG-SWS.