Semiconductor integrated circuit and radio communication apparatus using same

Abstract

An amplifier circuit unit including a signal amplifying is provided with a first bypass circuit unit for bypassing a part of an input signal to a ground side according to strength of the input signal, and a second bypass circuit unit for bypassing a part of the input signal to an output side according to the strength of the input signal, whereby gain attenuation control is effected. Also, the amplifier circuit unit is provided with a control circuit unit for decreasing a drain bias current of the signal amplifying when the first bypass circuit unit bypasses the part of the input signal to the ground side, and interrupting the drain bias current of the signal amplifying when the second bypass circuit unit bypasses the part of the input signal to the output side, whereby control of the drain bias current is effected.

Dependencies are inferred from the claim text.