Patent ID: 7157977
Filing Date: 2007-01-02
Classification: H03F,H03G

Abstract:
1. A feedback amplifier comprising: an input terminal detected an input voltage by an input current; a feedback amplification unit amplifying the input voltage to generate an output signal; and an output terminal outputting the output signal amplified by the feedback amplification unit, wherein the feedback amplification unit comprises a feedback circuit unit including a feedback resistor located between the input terminal and the output terminal, and a feedback transistor connected in parallel to the feedback resistor; and a bias circuit unit supplying a predetermined bias voltage to the feedback transistor in the feedback circuit unit and merged in the feedback amplification unit; wherein the bias circuit unit comprises a first bias transistor, a second bias transistor, a first bias resistor, and a second bias resistor, a base of the first bias transistor is connected to the base of the feedback transistor, a collector of the first bias transistor is connected to the base of the first bias transistor, and an emitter of the first bias transistor is connected to the first bias resistor, the first bias resistor grounded, and a base and a collector of the second bias transistor are connected to each other, an emitter of the second bias transistor is connected to the collector of the first bias transistor, and the collector of the second bias transistor is connected to the second bias resistor, the second bias resistor connected to the bias voltage.