Semiconductor integrated circuit for high frequency power amplifier and electric components with the semiconductor integrated circuit

Abstract

In a high frequency power amplifier circuit in which bias voltages are applied to the transistors for amplification by current mirroring, The power amplifier includes a detection circuit including a transistor for detection which receives the AC component of an input signal to the last-stage transistor for amplification at its control terminal, a current mirror circuit which mirrors current flowing through that transistor, and a current-voltage converter which converts current flowing in the slave side of the current mirror circuit into a voltage. In the detection circuit, a voltage from a bias circuit for generating the bias voltages for the transistors for amplification is applied to the control terminal of the transistor for detection, and output of the detection circuit is applied to the control terminal of the last-stage transistor for amplification.

Dependencies are inferred from the claim text.