Title :
Optimization of the watt-scale 220-GHz folded waveguide BWO
Author :
Jinchi Cai ; Huaibi Chen ; Linlin Hu ; Guowu Ma ; Hongbin Chen ; Xiao Jin
Author_Institution :
Dept. of Eng. Phys., Tsinghua Univ., Beijing, China
Abstract :
The latest development of 220 GHz folded waveguide (FW) backward wave oscillator (BWO) is presented here. The pill-box window system, beam optical system (BOS), slow wave structure (SWS) have been designed, machined and tested. However, the collector current of the prototype tube can just reach 13 mA with the emission current of 22 mA due to the imperfection of the structure and magnetic field, where no microwave signal detected. In previous SWS design, the threshold current is roughly estimated as 12 mA, which may become higher in real case. Apart from improving the assembly and brazing precision of the structure, the total number of periods is considered to be optimized to decrease the threshold current to 3 mA. The optimization result shows that the BWO can still output watt-scale power around 220 GHz.
Keywords :
backward wave oscillators; magnetic fields; millimetre wave oscillators; optimisation; slow wave structures; waveguides; BOS; FW BWO; SWS design; backward wave oscillator; beam optical system; brazing precision; collector current; current 13 mA; current 22 mA; current 3 mA; emission current; frequency 220 GHz; magnetic field; microwave signal; pill-box window system; slow wave structure; threshold current; watt-scale folded waveguide BWO; watt-scale power; Electron beams; Electron tubes; Optical waveguides; Optimization; Oscillators; Prototypes; Threshold current; BWO; folded waveguide; millimeter; watt; wave;
Conference_Titel :
Vacuum Electronics Conference (IVEC), 2015 IEEE International
Conference_Location :
Beijing
Print_ISBN :
978-1-4799-7109-1
DOI :
10.1109/IVEC.2015.7223891
