Apparatus and methods for wideband envelope tracking systems

摘要

Apparatus and methods for wideband envelope tracking systems are disclosed herein. In certain implementations, an envelope tracker includes a DC-to-DC converter, a current digital-to-analog converter (DAC), an error amplifier, a feedback circuit, and an AC combiner. The current DAC receives a digital envelope signal, and uses the digital envelope signal to generate an envelope current. The feedback circuit is connected between an output and an inverting input of the error amplifier, and the envelope current is provided to the error amplifier's inverting input. Additionally, the AC combiner generates a power amplifier supply voltage by combining an output of the DC-to-DC converter and an output of the error amplifier.

主权项

1. A method of envelope tracking in a power amplifier system, the method comprising:
generating a regulated voltage from a battery voltage using a DC-to-DC converter; generating a first envelope current based on a first digital envelope signal, including level-shifting a plurality of bits of the first digital envelope signal using a plurality of level-shifters, providing the plurality of level-shifted bits to a plurality of resistors, and generating the first envelope current based on a flow of current through the plurality of resistors; providing the first envelope current as an input to a first error amplifier, the first error amplifier electrically connected with negative feedback; and generating a first power amplifier supply voltage by combining the regulated voltage from the DC-to-DC converter and an output of the first error amplifier using a first AC combiner.