Patent ID: 9225308
Filing Date: 2015-12-29
Classification: H03F,H03G,H04B,H04L

Abstract:
1. An apparatus for amplifying a transmit signal, the apparatus comprising: a transmit path comprising a power amplifier module configured to be coupled to an antenna module, wherein the power amplifier module is configured to amplify a transmit signal; an envelope tracking path comprising a variable delay module and a power supply module, wherein the variable delay module is configured to vary a signal delay within the envelope tracking path according to a delay control parameter; and delay control circuitry configured to provide the delay control parameter based on a current characteristic transmit frequency of the transmit signal, wherein the current characteristic transmit frequency depends on a transmit band currently used for transmitting the transmit signal, a number of resource blocks currently used for transmitting the transmit signal and a current position of the used resource blocks within the used transmit band.