Radio-frequency amplifier with load response estimation

Patent metadata

Field	Value
Publication number	US-12463596-B2
Application number	US-202418736273-A
Country	US
Kind code	B2
Filing date	Jun 6, 2024
Priority date	Apr 29, 2022
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

An electronic device may include wireless circuitry with a processor that generates baseband signals, an upconversion circuit that upconverts the baseband signals to radio-frequency signals, a power amplifier, an antenna, and a transmit filter with a frequency dependent filter response coupled between the output of the power amplifier and the antenna. To help mitigate the frequency dependent filter response, the wireless circuitry may further include predistortion circuitry having an amplifier load response estimator that implements a baseband model of the filter response, an amplifier non-linearity estimator that models the non-linear behavior of the amplifier, and a control signal generator for adjusting the power amplifier based on the output of the amplifier load response estimator and the amplifier non-linearity estimator.

First claim

What is claimed is:

1 . Circuitry comprising:
a frequency upconversion circuit having an input configured to receive baseband signals and output corresponding radio-frequency signals; an amplifier configured to receive the radio-frequency signals; and a load response estimator coupled to the input of the frequency upconversion circuit and configured to receive signals generated based on the baseband signals and output an estimated load response associated with the amplifier.

2 . The circuitry of claim 1 , wherein the load response estimator is further configured to implement a baseband model derived from a frequency dependent load impedance at an output of the amplifier.

3 . The circuitry of claim 1 , further comprising:
a control signal generator configured to receive the estimated load response and having an output coupled to a control input of amplifier.

4 . The circuitry of claim 3 , wherein the control signal generator comprises:
an absolute value function generator configured to receive the estimated load response; and an envelope tracking power management circuit having an input coupled to the absolute value function generator and configured to output an adjustable power supply voltage to the control input of the amplifier.

5 . The circuitry of claim 3 , wherein the control signal generator comprises an absolute value function generator configured to receive the estimated load response and that is used to generate a bias signal to the control input of the amplifier.

6 . The circuitry of claim 3 , wherein the control signal generator comprises an envelope tracking power management circuit configured to generate an envelope tracking power supply voltage to the control input of the amplifier.

7 . The circuitry of claim 1 , further comprising:
a non-linearity estimator configured to receive the baseband signals and output non-linearity information to an input of the load response estimator.

8 . The circuitry of claim 7 , further comprising:
a feedback path configured to convey the estimated load response output from the load response estimator back to an input of the non-linearity estimator.

9 . The circuitry of claim 1 , further comprising:
a bandpass filter having an input impedance equal to a frequency dependent load impedance at an output of the amplifier.

10 . The circuitry of claim 2 , further comprising:
a control signal generator configured to receive the estimated load response and having an output coupled to a control input of amplifier, wherein the amplifier comprises:
a first amplifier configured to receive the radio-frequency signals; and
a second amplifier configured to receive the control signal from the control signal generator.

11 . The circuitry of claim 10 , further comprising:
a coupling circuit coupled to an output of the first amplifier and an adjustable impedance that is controlled by the second amplifier.

12 . The circuitry of claim 10 , further comprising a radio-frequency coupler that includes:
a first coupling component having a first terminal coupled to an output of the first amplifier and having a second terminal coupled to a transmit filter exhibiting a frequency dependent load impedance; and a second coupling component paired with the first coupling component, the second coupling component having a first terminal coupled to the output of the first amplifier and having a second terminal coupled to an output of the second amplifier.

13 . Circuitry comprising:
an upconverter configured to upconvert baseband signals to radio-frequency signals; an amplifier configured to receive the radio-frequency signals; a filter coupled to an output of the amplifier, the filter having a frequency dependent input impedance; and predistortion circuitry configured to receive the baseband signals and predistort the baseband signals in accordance with a baseband model that models the frequency dependent input impedance of the filter.

14 . The circuitry of claim 13 , wherein the predistortion circuitry is further configured to generate a corresponding control signal for the amplifier.

15 . The circuitry of claim 14 , wherein the control signal comprises a signal selected from one or more of: an adjustable power supply voltage for the amplifier, an adjustable bias voltage for the amplifier, a load modulation control signal for the amplifier, and an input signal to an additional amplifier coupled to the amplifier.

16 . The circuitry of claim 14 , wherein the predistortion circuitry comprises an envelope generator configured to produce the control signal for adjusting the amplifier.

17 . The circuitry of claim 13 , wherein the predistortion circuitry comprises:
a load response estimator implementing the baseband model; and a non-linearity estimator configured to model a non-linear behavior associated with the amplifier and non-linear effects associated with the filter.

18 . The circuitry of claim 13 , wherein the predistortion circuitry comprises a load response estimator implementing the baseband model.

19 . The circuitry of claim 13 , wherein the predistortion circuitry comprises a non-linearity estimator configured to model a non-linear behavior associated with the amplifier and non-linear effects associated with the filter.

20 . Circuitry comprising:
a frequency upconversion circuit having an input configured to receive baseband signals and output corresponding radio-frequency signals; an amplifier configured to receive the radio-frequency signals; a filter coupled to an output of the amplifier; and a non-linearity estimator coupled to the input of the frequency upconversion circuit and configured to model a non-linear behavior associated with the amplifier and non-linear effects associated with the filter.

Assignees

• Apple Inc

Inventors

• Henzler Stephan
• Langer Andreas

Classifications

• H04B1/0475 Primary

  with means for limiting noise, interference or distortion (H04B1/0483 takes precedence) · CPC title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title

• H04B2001/0416

  having gain or transmission power control · CPC title

• H03F3/211

  using a combination of several amplifiers (H03F3/60 takes precedence) · CPC title

• H03F2200/102

  A non-specified detector of a signal envelope being used in an amplifying circuit · CPC title