In this article an inverse modeling technique is used to design a 0.25 mum delta doped pseudomorphic high electron mobility transistor (PHEMT). The technique is based on the results obtained from the device simulator MEDICI. The technique has been used for determining the structural and physical parameters of the device for a defined threshold voltage, maximum trans conductance and the gate voltage at which the trans conductance peaks. Empirical formulas have been obtained based on a data bank created by varying the device structural parameters. Using these formulas, a 0.25 mum delta doped PHEMT has been designed and a good agreement has been obtained between the measured data and the predicted data. (C) 2004 American Vacuum Society.