Patent ID: 7679446

Claim:
A variable-gain low-noise amplifier comprising: a first load L 1 of which first terminal is connected to a power-source voltage Vdd and of which second terminal is connected to an output terminal Vo; a second load M 1 which is operated in response to a bias voltage Vb and of which first terminal is connected to the output terminal Vo; an input transistor M 2 of which first terminal is connected to the second terminal of the second load M 1 and of which gate is connected to an input terminal Vin; a pole/zero control circuit 210 which adjusts frequency characteristics and a gain in response to at least one pole/zero control signal CON 1 , of which first terminal is connected to the input terminal Vin, and of which second terminal is connected to the output terminal Vo; a gain control circuit 220 which adjusts the gain in response to at least one gain control signal CON 2 , of which first terminal is connected to a common terminal of the second load M 1 and the input transistor M 2 , and of which second terminal is connected to the input terminal Vin; and a third load L 2 of which first terminal is connected to a second terminal of the input transistor M 2 and a third terminal of the gain control circuit 220 and of which second terminal is connected to a ground voltage GND.