The dispersion effects of transconductance (gm) and output resistance (Rds) in AlGaN/GaN MODFETs were investigated. The dispersion effects of gm were found to be much smaller than those of Rds. Devices under different biases show gm dispersion of ∼ 4% to 7%, while Rds dispersion of ∼ 19% to 44% in a frequency range of 50 Hz to 100 kHz. The trapping-detrapping time constants of the dispersion effects were extracted by employing a novel distributed RC network and carrier injection current sources. The time constants estimated are in a range of ∼ 1.5 μs to 1 ms.
