Hybrid source follower amplifier

Abstract

Abstract A HYBRIDE SOURCE FOLLOWER AMPLIFIER IS DESCRIBED INCLUDING A FIELD EFFECT TRANSISTOR HAVING ITS SOURCE ELECTRODE CONNECTED TO A CAPACITIVE LOAD AND TO THE COLLECTOR OF A BIPOLAR TRANSISTOR AND HAVING ITS GATE ELECTRODE CONNECTED THROUGH A "FEED-FOWARD" CAPACITOR TO THE EMITTER OF SUCH BIPOLAR TRANSISTOR. THE FEED-FOWARD CAPACITOR IS EQUAL TO THE LOAD CAPACITANCE AND TRANSMITS HIGH FREQUENCY INPUT SIGNALS FROM THE INPUT TO THE OUTPUT OF THE AMPLIFIER THROUGH THE BIPOLAR TRANSISTOR ALONG A PATH WHICH BYPASSES THE INTERNAL GATE-TO-SOURCE CAPACITANCE OF THE FIELD EFFECT TRANSISTOR. THIS INCREASES THE HIGH FREQUENCY RESPONSE AND TENDS TO KEEP THE VOLTAGE ACROSS THE GATE-TO-SOURCE CAPACITANCE FROM CHANGING, THEREBY PROVIDING THE AMPLIFIER WITH A MORE CONSTANT INPUT CAPACITANCE AS WELL AS PREVENTING THE APPEARANCE OF A NEGATIVE INPUT RESISTANCE.

Inventors

• 👤 Glenn Bateman

Bibliographic Details