The design and fabrication of InxGa1-xAs Schottky barrier mixer diodes for space based heterodyne receivers

The difficulty in obtaining substantial local oscillator (LO) power at very high frequencies places an upper limit on the frequency range of heterodyne receiver systems. LO power can be reduced by using two diodes in an antiparallel configuration, but this requires the diodes to have low turn-on voltages. The design of an In_xGa _1-xAs Schottky barrier mixer diode with a turn-on voltage of less than 0.6 eV is presented here. Properties of the In_xGa _1-xAs material system which make it attractive for use with high-frequency devices are examined, and the dominant current mechanism for various doping levels and values of x (In mole fraction) is determined. A first-order analysis of the RF performance is presented, followed by a discussion of the fabrication procedure and initial results