Substrate optimization for a planar antenna of terahertz Si field effect transistor detectors

Abstract

Experimental and theoretical investigations of the influence of substrate thickness on the performance of Si field effect transistor terahertz detectors are presented.. We show that in the case of planar metal antennas a significant portion of incoming radiation, instead of being coupled to the transistors, may be coupled to the substrate leading to important responsivity losses.. The ways of avoiding these losses are discussed.