Apparatus and methods for envelope tracking systems

摘要

Apparatus and methods for envelope tracking systems are disclosed herein. In certain implementations, an envelope tracking system for generating a power amplifier supply voltage for a power amplifier is provided. The envelope tracking system includes a DC-to-DC converter that generates a regulated voltage from a battery voltage and controls a voltage of the regulated voltage using a low frequency feedback signal. The envelope tracking system further includes an error amplifier that generates an output current using an envelope signal and a high frequency feedback signal. The low frequency feedback signal is based on a low frequency component of the power amplifier supply voltage and the high frequency feedback signal is based on a high frequency component of the power amplifier supply voltage. The error amplifier generates the power amplifier supply voltage by adjusting the magnitude of the regulated voltage using the output current.

主权项

1. An envelope tracking system for generating a power amplifier supply voltage, the envelope tracking system comprising:
a DC-to-DC converter configured to generate a regulated voltage from a battery voltage, the DC-to-DC converter configured to control a voltage magnitude of the regulated voltage using a low frequency feedback signal that is based on a low frequency component of the power amplifier supply voltage; a high pass filter configured to generate a high pass filtered power amplifier supply voltage based on high pass filtering of the power amplifier supply voltage; a first comparator configured to generate a high frequency envelope signal based on comparing the high pass filtered power amplifier supply voltage to an envelope signal; and an error amplifier including an inverting input configured to receive a high frequency feedback signal that is based on a high frequency component of the power amplifier supply voltage, a non-inverting input configured to receive the high frequency envelope signal, and an output configured to generate an output current, the error amplifier configured to generate the power amplifier supply voltage by adjusting the magnitude of the regulated voltage using the output current.