APPARATUS AND METHODS FOR BIASING POWER AMPLIFIERS

摘要

Apparatus and methods for biasing power amplifiers are disclosed herein. In certain implementations, a power amplifier system includes a power amplifier and a bias circuit that generates a bias voltage for biasing the power amplifier. The bias circuit includes an amplifier, a current source for generating a reference current, and a reference transistor having a current therethrough that changes in relation to the bias voltage. The amplifier can control the bias voltage based on an error current corresponding to a difference between the reference current and the current through the reference transistor. The amplifier can be used to control the bias voltage such that the reference current and the current through the reference transistor are substantially equal.

主权项

1. A power amplifier system comprising:
a power amplifier configured to receive a radio frequency (RF) input signal, and to amplify the RF input signal to generate an RF output signal, the power amplifier further configured to receive a bias voltage that biases the power amplifier; and a bias circuit configured to generate the bias voltage, the bias circuit including a bias circuit amplifier, a current source configured to generate a reference current, and a reference transistor having a current therethrough that changes in relation to the bias voltage, the bias circuit amplifier configured to control the bias voltage based on an error current corresponding to a difference between the reference current and the current through the reference transistor.