Compact Terahertz SPICE Model: Effects of Drude Inductance and Leakage

We describe an improved compact SPICE/ADS model validated for the terahertz (THz) frequency range in a large dynamic range. The model validation was done by comparing the simulation results with the analytical THz detection theory and with the measured data for the 130-nm InGaAs/AlGaAs HFETs. This validation revealed the importance of the electron inertia and the crucial role of the gate and drain leakage currents at high intensities of the impinging THz radiation. The modeling results are in good agreement with the analytical THz detection theory and with the measured sub-THz response dependence on the bias, power, and polarization. It also demonstrates the response saturation previously measured at high intensities, and the resonant detection predicted by the detection theory for higher mobility devices. The model has been implemented in AIM-SPICE, ADS, and Cadence and could be used for design, characterization, and parameter extraction of sub-THz and THz devices and integrated circuits.