| 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 there through 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. |
