Split DAC Signal Paths for Lower-Power Digital Predistortion

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Solution Overview

Problem

Existing wireless communication devices face challenges in efficiently processing signals with digital predistortion (DPD) due to increased power consumption and bandwidth requirements, which are not adequately addressed by current single signal path architectures with a single DAC.

Innovation Solution

Separate the main signal path and predistortion signal path with distinct digital-to-analog converters (DACs) to process each signal independently, allowing for optimized power consumption and reduced thermal design specifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single DAC processes both main signal and predistortion signal in a single signal path, then device complexity is reduced, but power consumption increases and thermal design becomes more difficult

Engineering Contradiction:

Improvesignal path architectureVSAvoidpower consumption

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The patent divides the single signal path into two separate signal paths: a main signal path and a predistortion signal path. Each path has its own dedicated DAC (first DAC for main signal, second DAC for predistortion signal). This segmentation allows each DAC to be optimized independently for its specific signal type, reducing overall power consumption while maintaining device functionality.

Inventive Principle:

Principle #1Segmentation

2Ease of manufacture

If a single DAC processes both main signal and predistortion signal, then manufacturing is simpler, but thermal design specifications become more stringent

Engineering Contradiction:

ImproveDAC implementationVSAvoidthermal design specifications

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

By segmenting the signal processing into separate paths with dedicated DACs, the thermal load is distributed across multiple components rather than concentrated in a single DAC. This allows for more relaxed thermal design specifications as each DAC operates at lower power levels independently.

Inventive Principle:

Principle #1Segmentation

3Use of energy by moving object

If separate DACs are used for main signal and predistortion signal, then power consumption is reduced and thermal design is relaxed, but device complexity increases

Engineering Contradiction:

Improvepower consumptionVSAvoidsignal path architecture

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent applies local quality by optimizing each DAC for its specific signal characteristics. The first DAC is optimized for the main signal path while the second DAC is optimized for the predistortion signal path. This localized optimization allows each component to operate more efficiently, reducing overall power consumption despite the increased structural complexity.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250350305A1Split main and predistortion signal paths with separate digital-to-analog converters for supporting digital predistortion in transmitters

Publication Date: 2025.11.13 QUALCOMM INC

AI summary

Methods and apparatus for wireless communication using a transmitter capable of digital predistortion (DPD) and having a main signal path separated from a predistortion signal path, each path including a digital-to-analog converter (DAC). An example apparatus generally includes a main signal path comprising a first DAC, a power amplifier, and a combiner, the combiner being disposed in the main signal path between an output of the first DAC and an input of the power amplifier. The apparatus also includes a predistortion signal path comprising a second DAC, wherein the combiner is configured to combine a predistortion signal in the predistortion signal path with a main signal in the main signal path.