MICROWAVE MIXERS EMPLOYING MULTIPLE BARRIER SEMICONDUCTOR HETEROSTRUCTURE DEVICES

Experimental data on mixer performance of unipolar semiconductor heter ostructure diodes containing bulk alloy-ramp barriers are presented. P rototype Al(x)Ga1-xAs/GaAs heterostructures containing one, two, and f our barriers are fabricated by MBE and tested in a single-ended mixer circuit at 10 GHz. The devices with two and four barriers, which exhib it improved performance over the single-barrier device, achieve conver sion losses between 4 and 6 dB and noise temperature ratios between 1. 5 and 2 at 300 K. Several significant advantages over contending Schot tky diodes are also discussed. The results indicate that multiple-barr ier devices are good candidates for use in microwave and millimeter-wa ve mixer circuits.