Patent ID: 7580690
Filing Date: 2009-08-25
Classification: H03G

Abstract:
1. A high-frequency receiver comprising: a first input terminal to which a signal received by an antenna is input; a first amplifying circuit connected to the first input terminal; a second amplifying circuit to which an output signal of the first amplifying circuit is input; a mixer having a first input terminal to which an output signal of the second amplifying circuit is input and a second input terminal; an oscillator connected to the second input terminal of the mixer; a PLL circuit controlling an oscillation signal of the oscillator by a PLL; a third amplifying circuit to which an output signal of the mixer is input; a first output terminal to which an output signal of the third amplifying circuit is input; a first gain controller to which the output signal of the mixer is input and which gain-controls the second amplifying circuit by a first gain control voltage; a second gain controller to which the output signal of the third amplifying circuit is input and which gain-controls the third amplifying circuit by a second gain control voltage; a signal level determination unit for comparing a predetermined reference voltage with at least one of the first and second gain control voltages output from the first gain controller and the second gain controller; and a gain switch controller to which an output signal of the signal level determination unit is input, wherein the first amplifying circuit is gain-controlled by a gain switching signal output from the gain switch controller.