Multi-Frequency Impedance Matching Circuit for Plasma Reactors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current impedance matching solutions for capacitively coupled plasma reactors are impractical for multiple frequencies, requiring multiple power generators, match boxes, and filters, leading to power wastage and limited input power due to the need for separate impedance matching at each frequency.

Innovation Solution

A multi-frequency matching circuit design that adapts electrical impedance simultaneously for multiple frequencies using a single wideband power source, with adjustable components and additional stages as needed, to match the impedance seen by the generator to the output impedance of the power source, allowing for efficient power transfer across multiple frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple power generators, match boxes, and filters are used to achieve multi-frequency impedance matching, then impedance matching at multiple frequencies is achieved, but device complexity and power loss increase significantly

Engineering Contradiction:
Improvemulti-frequency impedance matching capabilityVSAvoidnumber of power generators, match boxes, and filters
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple impedance matching functions into a single matching network that can simultaneously match multiple frequencies. Instead of using separate match boxes for each frequency, one unified matching circuit with adjustable components handles all frequency bands, dramatically reducing system complexity while maintaining multi-frequency adaptability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The matching network is designed as a universal circuit that can operate across multiple frequency bands simultaneously. The circuit incorporates adjustable inductors and capacitors that can be tuned to achieve impedance matching at different frequencies, making a single device perform multiple frequency-specific functions

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If multiple power generators, match boxes, and filters are used for multi-frequency operation, then impedance matching is achieved, but power loss increases due to the need for filtering and isolation

Engineering Contradiction:
Improvemulti-frequency impedance matching capabilityVSAvoidpower loss from filtering and isolation
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

By merging multiple frequency paths into a single matching network, the patent eliminates the need for multiple filters and isolation components. The unified circuit processes all frequencies simultaneously without requiring energy-intensive filtering and separation, thereby reducing power loss

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent converts the challenge of handling multiple frequencies simultaneously into an advantage by designing a matching network that naturally accommodates multi-frequency operation. Instead of treating frequency interference as a harmful effect requiring filtering, the circuit is designed to harness multiple frequencies together, turning what would be noise into useful multi-frequency plasma excitation

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Device complexity

If a single wideband power source is used without impedance matching, then device complexity is reduced, but power transfer efficiency decreases due to impedance mismatch

Engineering Contradiction:
Improvenumber of power generators and match boxesVSAvoidpower loss from impedance mismatch
Core Design Contradiction:
Device complexityVSLoss of energy

Solution Approach 1:

The patent equips the single matching network with universal tuning capability that can adapt to different frequency bands and impedance conditions. The adjustable inductors and capacitors allow the circuit to optimize impedance matching across a wide frequency range, enabling efficient power transfer from a single wideband source without sacrificing adaptability

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The matching network incorporates dynamically adjustable components (variable inductors and capacitors) that can be tuned in real-time to match the impedance at different frequencies. This dynamic adjustment capability allows the single matching circuit to maintain optimal power transfer efficiency across varying frequency conditions

Inventive Principle:
Principle #15Dynamics

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

This solution enables efficient power transfer and optimal process performance by matching the impedance at multiple frequencies with fewer components, maximizing power transfer and allowing for flexible operation with unknown or varying impedance conditions.

Implementation Method 1

a matching circuit to adapt the electrical impedance seen by a power source at a plurality of frequencies, f n

Methodology Applied
Scientific EffectImpedance transformation: Electrical Impedance Tomography

Implementation Method 2

The tune circuit (4) comprises an inductance, L TUNE , and a capacitance, C TUNE , connected in series

Methodology Applied
Scientific EffectInductive reactance: Inductor

Implementation Method 3

The load circuit (5) comprises an inductance, L LOAD , and a capacitance, C LOAD , connected in parallel

Methodology Applied
Scientific EffectCapacitive reactance: Capacitance

Data Source

PatentEP2675064B1Electrical circuit to impedance match a source and a load at multiple frequencies, method to design such a circuit
Publication Date: 2020.02.12 ECOLE POLYTECHNIQUE
  • EP2675064B1 patent drawingFigure 1(a)~2
  • EP2675064B1 patent drawingFigure 3~4
  • EP2675064B1 patent drawingFigure 5~6b

AI summary

The invention concerns a matching circuit (3) to adapt electrical impedance simultaneously for at least one pair of a higher and a lower frequencies between a plasma reactor and a generator; said matching circuit comprises at least a "load and tune" L-type stage comprising: - a "tune circuit" (4) connected in series to the plasma reactor and comprising at least one of or both an inductor (LTune) and a capacitor (CTune) in series, - a "load circuit" (5) connected in parallel to the series-connected "tune circuit" and load, and comprising at least one of or both an inductor (LLoad) and a capacitor (CLoad) in parallel, the component values of the tune and load circuits are chosen such that, for the lower frequency, the matching circuit follows a negative load reactance path in a Smith chart, and for the higher frequency, the matching circuit follows a positive load reactance path in the Smith chart. The invention describes the extension of the design to enable such matching for multiple pairs of frequencies.