D.c. amplifier having fast recovery characteristics

Claim 1

A TRANSISTOR AMPLIFIER COMPRISING AN INPUT CIRCUIT CONNECTED BETWEEN THE BASE OF AN INPUT TRANSISTOR AND REFERENCE POTENTIAL, A CONSTANT CURRENT CIRCUIT CONNECTED BETWEEN SAID REFERENCE POTENTIAL AND THE EMITTER OF SAID INPUT TRANSISTOR, SAID CIRCUIT INCLUDING IN SERIES A SOURCE OF VOLTAGE A RESISTOR TO LIMIT THE MAXIMUM EMITTER CURRENT OF SAID INPUT TRANSISTOR FOR A SELECTED MAXIMUM CONDUCTIVITY THEREOF TO VALUES BELOW SATURATION OF SAID INPUT TRANSISTOR, A DIODE CONNECTED BETWEEN SAID EMITTER AND SAID REFERENCE POTENTIAL AND POLED TO PROVIDE A CONDUCTIVE PATH FROM SAID EMITTER TO GROUND FOR ALL VALUES OF CONDUCTIVITY BELOW SAID SELECTED MAXIMUM VALUE AND BECOMING SUBSTANTIALLY NONCONDUCTIVE FOR SAID SELECTED MAXIMUM VALUE OF CONDUCTIVITY, THE COLLECTOR OF SAID TRANSISTOR BEING COUPLED TO THE OUTPUT OF SAID AMPLIFIER, MEANS CONNECTED BETWEEN SAID COLLECTOR AND SAID REFERENCE POTENTIAL FOR (1) MAINTAINING AT HIGH FREQUENCIES THE COLLECTOR OF SAID INPUT TRANSISTOR AT A LOW IMPEDANCE WITH RESPECT TO SAID REFERENCE POTENTIAL AND (2) PRODUCING A MINIMUM CAPACITANCE BETWEEN SAID COLLECTOR AND ITS BASE, THEREBY TO MINIMIZE HIGH-FREQUENCY FEEDBACK TO SAID INPUT CIRCUIT.