RF POWER TRANSISTOR SECONDARY BREAKDOWN PROTECTION CIRCUIT

摘要

A protection circuit for RF power transistors to prevent secondary breakdown includes gate means to monitor both the collector current and collector voltage. A gate pulse generated each time the collector voltage exceeds a preset value is used to gate a wave form derived from the transistor collector current. When the current wave form is in phase with the gate pulse and is of sufficient amplitude, the gate means provides a controlled voltage to bias off the transistor power supply for purposes of reducing the output power to safe operating levels.