DIGITAL HYBRID MODE POWER AMPLIFIER SYSTEM

• US 20200136567A1
• Filed: 10/03/2019
• Published: 04/30/2020
• Est. Priority Date: 05/01/2002
• Status: Active Grant

• Current Assignee: Dali Wireless Inc. (Dali Systems Co., Ltd.)
• Original Assignee: Dali Systems Co., Ltd.
• Inventors: Kim, Wan Jong, Cho, Kyoung Joon, Stapleton, Shawn Patrick, Kim, Jong Heon, Yang, Dali
• Granted Patent: US 11,418,155 B2
• Time in Patent Office: Days
• CPC Class Codes: H03F 1/3247 using feedback acting on predistortion circuits H03F1/3264 takes precedence
• CPC Class Codes: H03F 1/3258 based on polynomial terms
• CPC Class Codes: H03F 2200/129 there being a feedback over the complete amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2201/3224 Predistortion being done for compensating memory effects
• CPC Class Codes: H03F 2201/3227 Adaptive predistortion based on amplitude, envelope or power level feedback from the output of the main amplifier
• CPC Class Codes: H03F 2201/3233 Adaptive predistortion using lookup table, e.g. memory, RAM, ROM, LUT, to generate the predistortion
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/20 Power amplifiers, e.g. Class B amplifiers, Class C amplifiers H03F3/26 - H03F3/30 take precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages

Abstract

A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by the narrowband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, the present invention could compensate the nonlinearities as well as memory effects of the power amplifier systems and also improve performances, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels. As a result, the digital hybrid mode power amplifier system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems, where baseband I-Q signal information is not readily available.

Claims

1. A digital hybrid mode power amplifier system comprising:

a down-converted RF input;

a multi-channel digital input;

a digital predistortion module for receiving at least one of the down-converted RF inputs or multi-channel digital inputs, wherein the digital predistortion module utilizes a predistortion polynomial;

a power amplifier portion responsive to signals representative of the output of the digital module; and

a down-converted feedback portion adapted to monitor signals representative of adjacent channel power for feeding back to the digital predistortion module signals representative of the output of one or more channels of the power amplifier portion, in response to which the digital predistortion module computes the predistortion polynomial and modifies its output to reduce adjacent channel power.