Bandwidth optimization for GaN HEMT terahertz detectors using the advanced SPICE model

Abstract

This paper presents a solution to address the problems for AlGaN/GaN HEMT terahertz detectors. An ASM GaN HEMT model is first developed and validated for the GaN HEMT terahertz detectors using ICCAP simulation. Then, a common-source amplification mode GaN HEMT amplifier with a large impedance is selected for integration with the detector, which offers a higher input impedance and thereby facilitates a better impedance match with the detector. An optimal bandwidth of 212.1 MHz was obtained when the gate voltage of the IF amplifier is at −1.8 V. Finally, the circuit matching is optimized between the GaN HEMT detector and the IF amplifier, and the bandwidth of the integrated chip reaches 626.0 MHz, representing an increase of about 195 % compared to the configuration without circuit matching.