GALLIUM ARSENIDE FIELD EFFECT TRANSISTOR MIXERS: THEORY ANDAPPLICATIONS.

THIS PAPER OUTLINES THE CONSIDERABLE ADVANTAGES OFFERED BY MICROWAVE GAAS METAL SEMICONDUCTOR FIELD EFFECT TRANSISTORS (MESFET) IN THE MIXER MODE. IT CONTAINS A MULTI-FREQUENCY, NONLINEAR ANALYSIS OF THE DEVICE, INDICATING CIRCUIT CONDITIONS FOR OPTIMUM PERFORMANCE IN TERMS OF CONVERSION GAIN. A NUMBER OF MICROWAVE INTEGRATED CIRCUITS (MIC) ARE DESCRIBED WHICH EXPLOIT THESE RESULTS FOR SINGLE AND DUAL GATE MESFETS AND WHICH CONFIRM THAT CONVERSION GAINS OF AROUND 5 DB AND 12GHZ ARE PRACTICALLY POSSIBLE. FURTHERMORE, SINGLE SIDEBAND NOISE FIGURES OF LESS THAN 6 DB HAVE BEEN MEASURED DEMONSTRATING THE OVERALL SUPERIORITY OF THIS TYPE OF MIC MIXER COMPARED WITH SIMILAR DIODE CIRCUITS.