A Modified Slow-Wave Structure for Backward-Wave Oscillator Design in THz Band

In this paper, a novel slow-wave structure (SWS), called quasi-parallel-plate (QPP), is proposed for terahertz (THz) backward-wave oscillator BWO design. Compared with the conventional SWSs, the novel SWS has a wider “cold” bandwidth and higher interaction impedance. The Particle-in-cell (PIC) results show that the BWO can produce over 0.82 W output power in the operating frequency range from 0.82 to 1 THz by utilizing an operating voltage range from 5 to 10 kV. The interaction efficiency over the entire operating frequency band is above 2.8%. This SWS, which employing a circular electron beam of 3 mA, can be considered as a promising THz SWS for BWO design with characteristics of moderate operating voltage, wide tunable bandwidth, high efficiency, and compact structure.