WT4 Millimeter Waveguide System: Semiconductor Devices for the WT4 Repeater

Abstract

Design, fabrication, performance, and reliability information is provided for three types of millimeter-wave diodes developed to operate over the 40-110 GHz WT4 band. A family of silicon I MP ATT diodes generate the transmitter and local-oscillator power. These diodes use an ion-implanted double drift impurity profile. A hermetically sealed package was developed to achieve high reliability. A diamond heat sink provides a low thermal resistance. A silicon PIN subnanosecond switching diode phase modulates the transmitted power. The passivated mesa of the PIN diode chip is fabricated from thin, high-resistivity epitaxial material to achieve low capacitance and fast switching. A gallium arsenide Schottky-barrier mixer diode down-converts the signal in the receiver. The beam-lead Schottky diode is fabricated using mo lecular beam epitaxy, which provides a novel junction-isolation tech nique. Also, a brief description is given of the salient features of other active devices which operate in the IF (1.371 GHz) and baseband (dc to 300 MHz) circuitry. They consist of a family of both transistors and diodes (step recovery device, PIN variolosser, and Schottky mixer).