Pulse-Mode Impedance Matching Using Reflection Coefficient Control

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Solution Overview

Problem

Traditional impedance matching methods face challenges such as convergence failure due to initial state dependency, instability near the matching position, and high dependency on load and transmission line impedance, leading to inefficient power transfer and control in electric systems like plasma and communication systems.

Innovation Solution

The proposed method employs a pulse mode impedance matching technique that measures electrical characteristics, determines control parameters based on pulse mode operations, and adjusts matching system settings accordingly, using a normalized characteristic vector and displacement vector to control variable reactive elements, thereby stabilizing the matching process even with varying load conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional impedance matching methods are used, then the matching process can be implemented, but convergence failure occurs due to dependency on initial state

Engineering Contradiction:
Improvematching convergenceVSAvoidinitial state dependency
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent transforms the impedance matching problem from Cartesian coordinates (real and imaginary parts of impedance) to polar coordinates (magnitude and phase of reflection coefficient). This parameter transformation creates a normalized matching criterion where the target is always at the origin, eliminating dependency on initial impedance values and ensuring reliable convergence regardless of starting conditions.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If traditional impedance matching methods are used, then the matching network can be controlled, but matching delay occurs due to instability near matching position

Engineering Contradiction:
Improvematching precisionVSAvoidmatching delay
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent implements a feedback control mechanism where the magnitude of the reflection coefficient is continuously measured and compared to a threshold value. When the reflection coefficient magnitude falls below the threshold, the system determines that impedance matching has been achieved and stops adjustments. This prevents oscillation near the matching point and eliminates matching delay caused by instability.

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If traditional impedance matching methods are used, then the matching network can be adjusted, but haunting issue occurs due to high dependency on load and transmission line impedance

Engineering Contradiction:
Improveimpedance matching capabilityVSAvoidcontrol stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent changes the control parameters from raw impedance values to normalized reflection coefficient magnitude and phase. This normalization makes the matching criterion independent of specific load and transmission line impedance values, allowing the system to adapt to various configurations while maintaining stable and reliable control without haunting issues.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2068441B1Impedance matching methods and systems performing the same
Publication Date: 2011.04.20 PLASMART CO LTD
  • EP2068441B1 patent drawingFigure 1~2
  • EP2068441B1 patent drawingFigure 3
  • EP2068441B1 patent drawingFigure 4

AI summary

Provided are an impedance matching method and a matching system performing the same. The method includes: measuring an electrical characteristic of the power transmission line; determining a pulse mode of the power source; extracting a control parameter for impedance matching from the electrical characteristic of the power transmission line; and controlling the matching system through the control parameter, wherein the matching system is controlled differently according to the pulse mode.