Design of Broad-Band Power GaAs FET Amplifiers

A model is presented for the drain-gate breakdown phenomenon of GaAs FET's, based on experimental results. this breakdown model is added to a previously published large-signal model and incorporated in a powerful computer-aided design program called LSFET. The program is capable of searching for the optimum power load for an FET and simulating the power performance of multistage amplifiers. The design of power amplifiers is discussed in detail, using the knowledge gained from LSFET. Data is presented from a fabricated monolithic broad-band power amplifier chip showing good agreement between measured results and simulated curves.