A new small-signal model of the dual-gate GaAs MESFET

A new small-signal model of the dual-gate GaAs MESFET (DGFET) is described. The model does not deal with the DGFET as a cascode connection of two single-gate FET (SGFET) parts but as a four-port device. The model parameters are extracted directly from the measured s-parameters. The new small-signal model is tested on sixteen devices at many bias conditions over the frequency range 0.5-26.5 GHz. The calculated S-parameters using the new small-signal model show very good agreement with the measured data.