A Bowtie Antenna Coupled Tunable Photon-Assisted Tunneling Double Quantum Well (DQW) THz Detector
AbstractThe integration of a bowtie antenna with a double electron layer tunneling transistor (DELTT) device for the purposes of THz detection is investigated in this paper. The concept of THz detection, based on photon-assisted tunneling (PAT) between the two electron layers in a double quantum well (DQW) heterostructure, will be explained. The detector is expected to have narrowband, electrically tunable, fast response, and the possibility to operate at relatively high temperatures. Since the active area of the detector is very small, which is necessary to achieve fast response, it is not efficient in collecting THz radiation. Therefore, a broadband bowtie antenna is integrated with the detector to efficiently collect the THz radiation. Characteristics of different bowtie antenna geometries at THz frequencies were studied. An equivalent circuit model of the THz detector was developed, for the first time, to estimate the impedance characteristics at THz frequencies. Such a model is crucial for achieving impedance matching between the DELTT and the antenna to increase the overall coupling efficiency.
Nonequilibrium Green's function theory of resonant steady state photoconduction in a double quantum well FET subject to THz radiation at plasmon frequency
