Impedance Matching Trajectory Control for Plasma Reactors

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Solution Overview

Problem

Existing impedance matching arrangements for high-frequency applications, such as plasma processes, are limited by the slow dynamics of mechanically driven variable reactances, leading to inefficient power delivery and prolonged operation under unfavorable load conditions during adaptation.

Innovation Solution

A method for determining a trajectory in the complex load plane based on predetermined criteria to quickly adjust the load impedance, allowing for faster impedance matching by optimizing the adjustment speed of reactances, which can be achieved using a logic circuit unit like an FPGA to control actuators such as motors or switching elements, ensuring efficient power delivery and minimizing reflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional impedance matching arrangements use mechanically driven variable reactances, then the structure is simple and reliable, but the adjustment speed is slow leading to prolonged operation under unfavorable load conditions

Engineering Contradiction:
Improveimpedance matching speedVSAvoidadaptation time
Core Design Contradiction:
SpeedVSLoss of time

Solution Approach 1:

The patent replaces mechanically driven variable reactances with electronically controllable reactances. The electronic reactances can be adjusted much faster than mechanical components, enabling rapid impedance matching without the inertia and mechanical wear limitations of motor-driven systems. This substitution directly addresses the slow adjustment speed problem while maintaining reliability through electronic control.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements dynamic adjustment of reactance values through electronic control systems that can rapidly change impedance parameters in response to load variations. The system continuously monitors load conditions and dynamically adjusts the electronic reactances to maintain optimal impedance matching, significantly reducing the adaptation time compared to static or mechanically adjusted systems.

Inventive Principle:
Principle #15Dynamics

2Productivity

If the direct path from current impedance value to reflection minimum is taken, then the adjustment is straightforward, but the reflected power decrease rate is slow

Engineering Contradiction:
Improvepower delivery efficiencyVSAvoidreflected power
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent determines an optimal trajectory for impedance adjustment in advance, considering the desired reflection power decrease rate as a criterion. By pre-calculating the optimal path through the complex load plane that maximizes the reflected power decrease rate, the system can proactively adjust reactance values along this predetermined trajectory rather than reacting slowly to load changes. This preliminary planning enables faster achievement of minimum reflected power conditions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the adjustment parameters by optimizing the trajectory in the complex load plane based on the criterion of reflected power decrease rate. Instead of using fixed or simple adjustment rules, the system dynamically determines reactance adjustment values that maximize the rate of reflected power reduction. This parameter optimization enables the system to achieve better power delivery efficiency more quickly by following an optimized adjustment path.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3369107B1Method for adjusting the impedance of a load to the output impedance of a power generator and impedance adjustment assembly
Publication Date: 2021.08.04 TRUMPF PATENTABTEILUNG
  • EP3369107B1 patent drawingFigure 1
  • EP3369107B1 patent drawingFigure 2~3
  • EP3369107B1 patent drawingFigure 4~6

AI summary

The invention relates to a method for adjusting the impedance of a load (28) to the output impedance of a power generator (40), comprising the following steps : a. generating a power by means of a power generator (40); b. supplying the power to a load (28) via an impedance adjustment assembly (10) with at least one reactance (18, 20, 22) that can be changed via a control element (12, 14, 16), wherein the impedance adjustment assembly (10) converts the load impedance (27) at the input of the load (18) into a transformed load impedance (29) at the input of the impedance adjustment assembly (10); c. detecting or determining a power reflected in the load (28) or at least a variable relating thereto; d. based on the reflected power of the at least one related variable, checking whether a maladjustment has occurred; e. determining a trajectory (50) in a complex load plane, in particular in the Smith chart (60), according to at least one predetermined criterium; f. controlling the at least one control element (12, 14, 16) such that the transformed load impedance (29) follows the trajectory (50).