ACTIVE SOLID-STATE DEVICES

This 'paper describes the electrical and physical characteristics of 20 new solid‐state devices developed for TD‐3. Among them are new high‐frequency planar, epitaxial, NPN silicon transistors which are used in intermediate‐ frequency amplifiers and in the FM deviator. The microwave power for the transmitter and receiver is supplied from a three‐stage varactor multiplier chain which uses three new epitaxial silicon varactor diodes. A high‐quality epitaxial silicon varactor diode pair is the up‐converter in the transmitter modulator. A new epitaxial gallium arsenide Schottky barrier mixer diode assures a low noise figure for the receiver modulator. Two point‐contact silicon IF and RF monitor diodes were developed using the same miniature package in which the transmitter modulator and receiver modulator diodes are encapsulated. Two very stable diffused silicon diodes provide a stable output from the FM deviator‐, in‐process preaging at accelerated conditions is used to assure satisfactory stability. Two new epitaxial silicon Schottky barrier diodes are used in tile IF amplifier‐limiter and discriminator circuits, which require a nonlinear resistance with negligible capacitance and recovery time. Stringent voltage breakdown, corona and mounting requirements for the high voltage power supply rectifiers were satisfied by molding two high‐ voltage diode rectifier assemblies in a high‐dielectric plastic. The need for a ‐pure variable resistance in the IF variolosser was satisfied by the development of a new silicon PIN diode. © 1968 The Bell System Technical Journal