Swarm intelligence - Based small signal parameters extraction for PHEMT

A proposed small-signal model parameters for a pseudomorphic high electron mobility transistor (PHEMT) is presented. Both extrinsic and intrinsic circuit elements of a small-signal model are determined using particle swarm population-based search method as a global search and optimization tool. The parameters extraction of the small-signal model is performed on 200 mum gate width AlGaAs/InGaAs PHEMT. The equivalent circuit elements for a proposed 18-elements model are determined directly from the measured S- parameters. The optimizer is used to extract the parameters of the proposed small-signal model from 0.5 up to 18 GHz.The validity of the proposed small signal model is verified by comparing the simulated small signal S-parameters with the measured data of a 0.25 mum by 200 mum gate PHEMT.