US 11,606,068 B2 · Power amplifier linearizer

Abstract

Circuits and methods for achieving good amplifier AM-AM and AM-PM metrics while achieving good power, PAE, linearity, and EVM performance. Embodiments compensate for a non-linear distortion profile (e.g., an AM-PM and/or AM-AM profile) in an amplifier by pre-processing an input signal, such as a radio-frequency signal, to alter the non-linear distortion profile of the input signal so as to compensate for the non-linear distortion profile imposed by a coupled device, such as an amplifier. An inventive aspect includes linearizing an output from an amplifier having a first non-linear distortion profile, including passing an input signal having a second non-linear distortion profile through a reflective hybrid coupler to a non-linear termination circuit, and reflecting a modified input signal from the non-linear termination circuit back through the reflective hybrid coupler as an output signal, the output signal having a third non-linear distortion profile shaped to compensate for the first non-linear distortion profile.

Claims23

Dependent claims

A linearizer circuit, including:

(a) a reflective hybrid coupler configured to receive an input signal to be linearized, the input signal having a first non-linear distortion profile;
and
(b) a non-linear termination circuit coupled to the reflective hybrid coupler and configured to reflect a modified input signal back through the reflective hybrid coupler as an output signal, the output signal having a second non-linear distortion profile, wherein the non-linear termination circuit includes:
(1) a first reflective modulation device including a first field-effect transistor (FET) having a gate, a drain, and a source, wherein the gate of the first FET is coupled to the direct port of the reflective hybrid coupler;
and
(2) a second reflective modulation device including a second FET having a gate, a drain, and a source, wherein the gate of the second FET is coupled to the coupled port of the reflective hybrid coupler;
(c) a first load inductor coupled to the drain of the first FET of the first reflective modulation device and configured to be coupled to a voltage supply;
and
(d) a second load inductor coupled to the drain of the second FET of the second reflective modulation device and configured to be coupled to the voltage supply.

6 more elements

A linearizer circuit for an amplifier, including:

(a) a reflective hybrid coupler configured to receive an input signal to be linearized, the input signal having a first amplitude-to-phase modulation (AM-PM) profile, the reflective hybrid coupler including:
(1) an input port for receiving the input signal;
(2) a direct port;
(3) a coupled port;
and
(4) an output port configured to be coupled to an amplifier having a second AM-PM profile;
(b) a first reflective modulation device including a first field-effect transistor (FET) having a gate, a drain, and a source, wherein the gate of the first FET is coupled to the direct port of the reflective hybrid coupler;
(c) a second reflective modulation device including a second FET having a gate, a drain, and a source, wherein the gate of the second FET is coupled to the coupled port of the reflective hybrid coupler;
(d) a first load inductor coupled to the drain of the first FET of the first reflective modulation device and configured to be coupled to a voltage supply;
and
(e) a second load inductor coupled to the drain of the second FET of the second reflective modulation device and configured to be coupled to the voltage supply;
wherein the first and second reflective modulation devices modify the first AM-PM profile of the input signal to a modified output signal having a third AM-PM profile that is provided to the amplifier through the output port of the reflective hybrid coupler, the third AM-PM profile compensating the second AM-PM profile to a more linear AM-PM profile for an amplified output signal from the amplifier.

9 more elements

Dependencies are inferred from the claim text.

Power amplifier linearizer

Life of this patent

Power amplifier linearizer

Life of this patent

Abstract

Claims23