Enhanced responsivity in a novel AlGaN / GaN plasmon-resonant terahertz detector using gate-dipole antenna with parasitic elements

Plasmon-resonant terahertz (THz) detection using heterojunction field effect transistors (HFETs) is a promising method to enable compact and efficient THz detectors which can be applied to real-time imaging systems or THz spectroscopic analysis [1–2]. So far, the plasmon-resonant detectors which receive sub-THz and THz radiation at a gate bonding-wire or an external antenna have been reported [3–5]. However, the signal transmission from the antenna to the FET causes large propagation loss which degrades the sensitivity. In this paper, we present a novel AlGaN / GaN heterojunction FET which can detect THz radiation directly at a gate electrode with high responsivity.