Patent ID: 6046639
Filing Date: 2000-04-04
Classification: H03B,H03F

Abstract:
An amplifier circuit comprising:(a) a common-emitter amplifier including a single first bipolar transistor;an input signal being applied to a base of said first bipolar transistor, thereby producing a first and a second output signal;said first output signal of said common-emitter amplifier being derived from said base of said first bipolar transistor;said second output signal of said common-emitter amplifier being derived from a collector of said first bipolar transistor;(b) a first level converter for converting a dc level of said first output signal of said common- emitter amplifier to a first dc level;(c) a second level converter for converting a dc level of said second output signal of said common-emitter amplifier to a second dc level; and(d) a differential amplifier including a first and a second input terminal and a first and a second output terminal;a dc level at said first input terminal of said differential amplifier being equal to said first dc level;a dc level of said second input terminal of said differential amplifier being equal to said second dc level;wherein said first output signal of said common-emitter amplifier is applied to said first input terminal of said differential amplifier through said first level converter, thereby producing a first output signal of said differential amplifier at said first output terminal;and wherein said second output signal of said common-emitter amplifier is applied to said second input terminal of said differential amplifier through said second level converter, thereby producing a second output signal of said differential amplifier at said second output terminal.