Switched-Capacitor Tracker Circuit for Digital ET Power Efficiency

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Solution Overview

Problem

Further improvement in power efficiency is desired in the digital ET mode of supplying discrete voltages to a power amplifier.

Innovation Solution

A tracker circuit comprising a switched-capacitor circuit and a supply modulator that generates and selectively outputs discrete voltages based on the difference between variable input voltages, including a first input voltage and a second input voltage lower than the first, to a power amplifier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If discrete voltages are supplied to power amplifier in digital ET mode, then power efficiency is improved, but further improvement in power efficiency is desired

Engineering Contradiction:
Improvepower efficiencyVSAvoidtracker circuit complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The power supply voltage is segmented into multiple discrete voltage levels (e.g., Vmax, Vmid, Vmin) that can be selectively applied to the power amplifier. The switched-capacitor circuit divides the voltage range into distinct steps, allowing the system to operate at optimal efficiency points for different signal conditions without requiring a continuously variable power supply.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tracker circuit dynamically switches between different discrete voltage levels based on the instantaneous signal envelope and operational conditions. The supply modulator continuously adjusts which discrete voltage is applied to the power amplifier, enabling real-time optimization of power efficiency while maintaining adaptability to varying signal requirements.

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If multiple discrete voltages are generated, then power efficiency is improved, but circuit complexity increases

Engineering Contradiction:
Improvepower efficiencyVSAvoidswitched-capacitor circuit complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The switched-capacitor circuit merges multiple voltage generation functions into a single integrated structure. By using capacitive switching networks, the circuit generates multiple discrete voltage levels from a single power supply rail, eliminating the need for separate voltage regulators or power supply circuits for each voltage level.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The circuit changes the electrical parameters (voltage levels) by switching capacitor connections rather than using multiple physical voltage sources. The switched-capacitor network alters the effective voltage presented to the power amplifier by reconfiguring capacitor arrangements, enabling discrete voltage generation through topological changes rather than additional hardware.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Improves power efficiency by dynamically regulating power supply voltage to the power amplifier, enhancing performance in digital ET mode.

Implementation Method 1

a switched-capacitor circuit configured to generate a plurality of discrete voltages

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4604393A1Tracker circuit, communication device, and tracking method
Publication Date: 2025.08.20 MURATA MFG CO LTD
  • EP4604393A1 patent drawingFigure 1A~1C
  • EP4604393A1 patent drawingFigure 2
  • EP4604393A1 patent drawingFigure 3

AI summary

A tracker circuit (1) includes a switched-capacitor circuit (20) configured to generate a plurality of discrete voltages and a supply modulator (30) configured to selectively output at least one of the plurality of discrete voltages to a power amplifier (2). Based on a difference between a first input voltage and a second input voltage that is variable and that is lower than the first input voltage, the switched-capacitor circuit (20) is configured to generate the plurality of discrete voltages.