Input protection circuit

摘要

A depletion-mode MESFET is connected between an RF input terminal and ground. The gate is connected to a negative reference voltage via a bias resistor and to ground via a capacitor. A detector couples the input terminal to the gate and includes first and second series diodes and a second resistor connected from between the first and second diodes to ground. A coil is connected between the input terminal and an output terminal connected to a GaAs integrated circuit. A Schottky diode limiter is connected to the output terminal for limiting the voltage of both positive and negative polarities that leak to the output terminal from the transistor.