Patent ID: 7439809
Filing Date: 2008-10-21
Classification: H03F

Abstract:
1. A Radio Frequency (RF) power amplifier comprising: an RF power amplifier transistor; a bias supply circuit for supplying a bias current to a base of the RF power amplifier transistor; and a bias control circuit connected between the base of the RF power amplifier transistor and the bias supply circuit, wherein the bias control circuit is constructed to control the bias current of the RF power amplifier transistor in accordance with a power supply voltage of the RF power amplifier transistor, and the bias control circuit comprises a bias control transistor having a collector connected between the output of the bias supply circuit and the base of the RF power amplifier transistor, and an inverter transistor having a collector connected to the base of the bias control transistor, the base of the inverter transistor being connected to the power supply of the RF power amplifier transistor.