Broad-Band Internal Matching of Microwave Power GaAs MESFET's

Broad-band internal matching techniques for high-power GaAS MESFET's at C band have been developed adopting novel circuit configurations and large-signal characterizations in the circuit design. The lumped-element two-section input matching network is formed on a single ceramic plate with a high dielectric constant. The semidistributed single-section output circuit is formed in microstrip pattern on an alumina plate. The internally matched GaAs FET with 11200-mu m total gate width developed has a 2.5-W power output at 1-dB gain compression and a 4.4-W saturated power output with 5.5-dB linear gain from 4.2 to 7.2 GHz without external matching. The FET internally matched from 4.5 to 6.5 GHz exhibited 5-W saturated power output with 6-dB linear gain.