Simplified Analytical Approach of Designing Slow- Wave-Structure for a Compact, High Power, Terahertz Source for Spectroscopy, Imaging and Radar

Abstract

Compact, coherent, high power, THz sources of frequency varying from 0.1THz to 5THz are required for their numerous applications in Spectroscopy, Imaging, Radar, etc. There are need for both CW and pulsed THz sources of broad bandwidth and wide tuning range. Different types of THz sources based on optical device, solid state device and vacuum electronic device (VED) are compared. VED is selected for further investigation because of its high power, high efficiency and low cost. Among VEDs, backward wave oscillator (BWO) is the most preferred THz source because of its compact size, simplicity and wide tuning range. Simplified analytical approach is presented for designing slow-wave-structure (SWS) for a THz BWO. Designs for two BWOs of 0.22THz, 100W output power, and of 1.2THz, 1W output power are presented. Planar RF structure is selected for BWO because it is easier to fabricate by MEMS technology with high precision and surface finish.