A Compact Current- and Voltage-Mode Model of Antenna-Coupled FET Terahertz Detectors

In this article a comprehensive modeling of cold-biased field-effect transistors (FETs) used as terahertz (THz) detectors is developed. The described model is based upon the transistor Enz-Krummenacher-Vittoz (EKV) model in order to provide valid quantities also near and below the transistor threshold by using available technology parameters, without any extra fitting nor calibration. Important aspects such as the antenna coupling and the effect of amplitude modulation of the THz source are considered in a single, handy, analytical model. THz measurements performed on specifically designed FET detectors confirm its validity, providing a powerful tool and giving a clear insight of the role of available variables. The model can anticipate time-consuming numerical simulations or more physically accurate models requiring experimental parameters calibration, that may complement the results for better accuracy.