Noise optimized envelope tracking system for power amplifiers

摘要

A radio frequency (RF) power amplifier system that comprises a power amplifier configured to amplify an RF input signal to generate an RF output signal. The power amplifier has a gain that is controlled by a supply voltage to the power amplifier. An amplitude detector is configured to generate an amplitude signal indicative of an amplitude of the RF input signal. A power supply generates the supply voltage to the power amplifier based on the amplitude signal indicative of the amplitude of the RF input signal. The gain of the power amplifier is allowed to have variations over the amplitude range of the RF input signal in favor of having a supply voltage that is monotonic relative to the amplitude of the RF input signal across an amplitude range of the RF input signal.

主权项

1. A radio frequency (RF) power amplifier system comprising:
a power amplifier configured to amplify an RF input signal to generate an RF output signal, a gain of the power amplifier controlled by a supply voltage to the power amplifier; an amplitude detector configured to generate an amplitude signal indicative of the amplitude of the RF input signal; and a power supply configured to generate the supply voltage to the power amplifier based on the amplitude signal indicative of the amplitude of the RF input signal, the supply voltage being monotonic relative to the amplitude of the RF input signal across an amplitude range of the RF input signal, wherein, during a first portion of the amplitude range of the RF input signal, the gain of the power amplifier is substantially constant while the supply voltage is adjusted monotonically relative to the amplitude of the RF input signal, and wherein, during a second portion of the amplitude range of the RF input signal, the gain of the power amplifier is substantially non-constant while the supply voltage is adjusted monotonically relative to the amplitude of the RF input signal.