Design and Development of Ultra Wide-Band Microwave Components for Snow-Probing Radars

Abstract

This thesis describes the design and development of two different ultra-wideband microwave circuits for snow-probing radars. First, a broadband, low-loss planar quadrature hybrid coupler for the 2-20 GHz range is presented. The coupler offers better performance than commercially available options in terms of phase/amplitude imbalance and form factor. Next, a broadband, high-power T/R module with fast switching and integrated LNA is demonstrated to enable high altitude and multi-channel modes of operations of the CReSIS airborne snow radar along with automated surface tracking ability. The modules include a custom medium-power switch with an overall order of magnitude performance increase compared to commercially available duplexers/SPDT switch solutions. Pulsed mode operations at peak power levels exceeding 100 Watts (conservatively) can be supported with these devices and a demonstrated switching speed of less than 400 ns.