Patent ID: 8040186

Claim:
A radio frequency amplifier circuit for amplifying a radio frequency signal, comprising: a bias circuit operable to generate a bias current, wherein an amount of the bias current is changeable in accordance with a control signal, and an amplifier operable to amplify, by using the bias current supplied by the bias circuit, the radio frequency signal having been inputted thereto, wherein each of the first bias circuit and the second bias circuit includes: a bias supply transistor operable to supply, to each of the first amplifier and the second amplifier, each of the first bias current and the second bias current in accordance with a base current supplied thereto; a first temperature compensation transistor operable to pass a current in accordance with a reference voltage; a second temperature compensation transistor operable to correct, in accordance with the current passed by the first temperature compensation transistor, the base current to be supplied to the bias supply transistor, so as to compensate a temperature characteristic represented by the bias supply transistor; and a bias changing section, connected to a base of the second temperature compensation transistor, operable to change, in accordance with the control signal, an amount of the base current to be supplied to the bias supply transistor.