Dynamic bias current adjustment for power amplifiers

摘要

In one embodiment, a circuit comprises a power amplifier. The circuit further comprises a memory that stores bias current values corresponding to a plurality of frequencies across a frequency band for setting the bias of a power amplifier based on selected frequencies, and a controller configured to provide at least one bias current value corresponding to a selected frequency from the memory to the power amplifier in response to a frequency selection signal. The bias current value at each frequency may be selected to maximize power efficiency or minimize adjacent channel leakage-power ratio of the power amplifier at said frequency. In one embodiment, the memory further stores bias current values corresponding to the plurality of frequencies across the frequency band at a plurality of temperatures for setting the bias of a power amplifier based on a temperature of the power amplifier and on selected frequencies.

主权项

1. A circuit comprising:
a power amplifier comprising one or more power stage transistors; a memory that stores bias current values corresponding to a plurality of frequencies across a frequency band for setting bias of the one or more power stage transistors of the power amplifier based on selected frequencies; a controller configured to provide at least one bias current value corresponding to a selected frequency from the memory to the power amplifier in response to a frequency selection signal, wherein a first terminal of a first power stage transistor of the one or more power stage transistors is configured to receive a radio frequency input signal and a second terminal of the first power stage transistor is configured to receive a power supply voltage that changes based on the radio frequency input signal; and a feedback system for biasing the power amplifier during operation, wherein the feedback system is operable to evaluate an output signal of the power amplifier and to select a bias current value for the frequency of the output signal based on a performance metric of the power amplifier.