Title :
A THz Backward-Wave Oscillator Based on a Double-Grating Rectangular Waveguide
Author :
Qing-Lun Liu ; Zi-Cheng Wang ; Pu-Kun Liu ; Chao-Hai Du ; Hai-Qiang Li ; An-Yu Xu
Author_Institution :
Inst. of Electron., Beijing, China
Abstract :
A double-grating rectangular waveguide system with a round beam channel is proposed as the slow-wave interaction structure of a terahertz (THz) backward-wave oscillator (BWO). Applying the latest microfabrication techniques, the interaction structure is fully realizable and easily assembled. The basic design principle including the beam-wave dispersion relation, interaction impedance, and the system configuration is presented. A detailed sensitivity analysis of this THz BWO circuit is carried out to investigate the structure errors caused by fabrication and brazing. Both upstream and downstream ends are loaded with step tapers to improve the voltage standing wave ratio. The downstream reflection is absorbed by a linear attenuator. The round electron beam is generated by a pierce gun with compression ratio of 15. A 3-D particle-in-cell simulation demonstrates a broad electronic tunable bandwidth, a 3-dB bandwidth exceeding 28 GHz with highest output power 16 W, and interaction efficiency 3.57%.
Keywords :
backward wave oscillators; brazing; electron guns; microfabrication; rectangular waveguides; sensitivity analysis; slow wave structures; 3D particle-in-cell simulation; THz BWO circuit; THz backward-wave oscillator; beam-wave dispersion relation; brazing; double-grating rectangular waveguide system; downstream reflection; efficiency 3.57 percent; interaction impedance; interaction structure; linear attenuator; microfabrication techniques; pierce gun; power 16 W; round beam channel; round electron beam; sensitivity analysis; slow-wave interaction structure; structure errors; terahertz backward-wave oscillator; voltage standing wave ratio; Attenuators; Dispersion; Gratings; Impedance; Oscillators; Power generation; Rectangular waveguides; Backward-wave oscillator (BWO); double-grating rectangular waveguide; slow-wave structure (SWS); terahertz wave;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2013.2246868