Invited Talk by Nuria Llombart

Author: Nuria Llombart; Universidad Complutense de Madrid; Spain
Title of the Talk Quasioptical Time-Delay Multiplexing for a Terahertz Imaging Radar
Abstract:
Time-delay multiplexing is a method where the frame rate of a single-transceiver terahertz imaging radar can be doubled by splitting the transmitted beam into two beams of orthogonal polarization, and then scanning the beams over two separate regions of a target simultaneously. We previously demonstrated multiplexing at 4 m standoff distances in a 670 GHz imaging radar, using waveguide components to split the beams rotate their polarization. However, significant ohmic losses through the waveguide components were measured, and finite transmit/receive coupling contributed to a substantial dynamic range reduction. In this contribution we demonstrate radar multiplexing in a 670 GHz imaging radar operating at longer standoff distances of 25 m, and we present an all-quasioptical approach for beam splitting and polarization rotation. By eliminating the extra waveguide components, we have achieved a frame rate doubling from 0.5 to 1 Hz with negligible signal attenuation or leakage.