Methods and apparatus for envelope tracking system

摘要

A communication unit includes a radio frequency, RF, transmitter having: a power amplifier, PA, module; and an envelope tracking system operably coupled to the PA module and having a supply modulator arranged to variably control a supply voltage for the PA module in response to a number of input samples of an envelope signal; wherein the envelope tracking system further includes at least one slew rate module arranged to re-distribute a maximum slew rate across the number of input samples in a provision of a variable power supply to the PA module.

主权项

1. A communication unit comprising:
a radio frequency, RF, transmitter comprising:
a power amplifier, PA, module; andan envelope tracking system operably coupled to the PA module and comprising a supply modulator arranged to variably control a supply voltage for the PA module in response to a number of input samples of an envelope signal; wherein the envelope tracking system further comprises at least one slew rate module arranged to re-distribute a maximum slew rate across the number of input samples in a provision of a variable power supply to the PA module, and the supply modulator comprises at least one DC-DC converter operably coupled to a linear amplifier arranged to generate the variable power supply to the PA module, such that the at least one slew rate module provides the re-distributed maximum slew rate across the number of input samples of the envelope signal to the at least one DC-DC converter.