Systems and methods for impedance matching in plasma creation at atmospheric pressure

1 . A system comprising:

a matching network, where the matching network comprises:

receiving circuitry to receive magnitude and phase control signals from an RF power source for combined electrical power;

a variable load capacitor;

a variable phase capacitor; and

tuning circuitry coupled to the receiving circuitry, the tuning circuitry responsive to the magnitude and the phase control signals to tune an impedance presented to the RF power source:

wherein the impedance is tuned by independently adjusting each of the variable load capacitor and the variable phase capacitor;

wherein components of a line voltage related signal collected from the RF power source are rectified to produce the magnitude control signal used to tune the impedance presented to the RF power source.

2 . The system of claim 1 , further including a detector receiving combined electrical power comprising both forward power and reflected power and electrically coupled to the receiving circuitry to receive the magnitude and phase control signals, the detector including calculating circuitry to calculate a magnitude DC voltage indicator signal and a phase DC voltage indicator signal in real time.

3 . The system of claim 2 , where the calculating circuitry calculates the magnitude and phase control signals in real time by performing the operations including:

converting at least a first portion of the combined electrical power into a first current signal;

converting at least a second portion of the combined electrical power into a first voltage signal;

creating the magnitude DC voltage indicator signal using the first current signal and the first voltage signal;

converting at least a third portion of the combined electrical power into a second current signal;

converting at least a fourth portion of the combined electrical power into a second voltage signal; and

creating the phase DC voltage indicator signal using the second current signal and the second voltage signal.

4 . The system of claim 1 , further comprising a first cable connector for receiving RF electrical power from the RF power source; and

a second cable connector to output the RF electrical power.

5 . The system of claim 2 , further comprising:

a power controller located within a power controller housing different from a matching network housing that includes the matching network; and

an atmospheric pressure plasma creation device located within a plasma creation device housing different from the matching network housing;

wherein the power controller is electrically coupled to the matching network via a first RF cable, and wherein the atmospheric pressure plasma creation device is electrically coupled to the matching network via a second RF cable.

6 . The system of claim 5 , wherein the detector is contained within the power controller housing.

7 . The system of claim 5 , wherein the detector is a standalone device.

8 . The system of claim 2 , wherein:

the tuning circuitry to adjust the variable phase capacitor is capable of moving the variable phase capacitor to a new phase position, the new phase position of the variable phase capacitor being calculated as a current phase capacitor position added to the phase DC voltage indicator signal multiplied by a phase gain; and

wherein the tuning circuitry to adjust the variable load capacitor is capable of moving the variable load capacitor to a new load position, the new load position of the variable load capacitor being calculated as a current load capacitor position added to the magnitude DC voltage indicator signal multiplied by a magnitude gain.

9 . A method comprising:

receiving, at a matching network, electrical power by way of a first RF cable;

receiving a magnitude control signal, and a phase control signal;

tuning, based on the received magnitude control signal and the received phase control signal, an impedance of the electrical power by independently adjusting a variable load capacitor and a variable phase capacitor; and

outputting the electrical power comprising the tuned impedance by way of a second coaxial cable;

wherein components of a line voltage related signal collected from a RF power source are rectified to produce the magnitude control signal used to tune the impedance of the electrical power.

10 . The method of claim 9 , wherein the tuning of the impedance includes tuning instructions for:

adjusting based on a magnitude DC voltage indicator signal, the variable load capacitor until the magnitude DC voltage indicator signal is substantially zero; and

adjusting, based on a phase DC voltage indicator signal, the variable phase capacitor until the phase DC voltage indicator signal is substantially zero,

wherein the adjusting of the variable phase capacitor is performed independently of the adjusting the variable load capacitor.

11 . The method of claim 10 , further comprising calculating the magnitude DC voltage indicator signal and the phase DC voltage indicator signal in real time.

12 . A method comprising:

receiving, at a detector, combined electrical power comprising both forward power and reflected power in a system that includes an atmospheric pressure plasma creation device configured to operate at atmospheric pressure, the combined electrical power having an impedance;

converting the combined electrical power into a magnitude DC voltage indicator signal and a phase DC voltage indicator signal;

calculating, at a processor, instructions to tune the impedance to independently adjust a magnitude and a phase of the combined power;

sending the instructions via a signaling cable to a matching network; and

tuning the impedance according to the instructions.

13 . The method of claim 12 , wherein the matching network comprises a standalone matching network.

14 . The method of claim 12 , wherein the converting of the combined electrical power includes:

converting at least a first portion of the combined electrical power into a first current signal;

converting at least a second portion of the combined electrical power into a first voltage signal;

creating, using the first current signal and the first voltage signal, a magnitude DC voltage indicator signal;

converting at least a third portion of the combined electrical power into a second current signal;

converting at least a fourth portion of the combined electrical power into a second voltage signal; and

creating, using the second current signal and the second voltage signal, a phase DC voltage indicator signal;

wherein the tuning of the impedance includes:

adjusting, based on the magnitude DC voltage indicator signal, a load capacitor until the magnitude DC voltage indicator signal is substantially zero; and

adjusting, based on the phase DC voltage indicator signal, a phase capacitor until the phase DC voltage indicator signal is substantially zero;

wherein the adjusting of the phase capacitor is performed independently of the adjusting of the load capacitor.

15 . The method of claim 14 , wherein the creating of the magnitude DC voltage indicator signal comprises:

scaling at least one of the first voltage signal and the first current signal to make the first voltage signal similar to the first current signal;

rectifying the first voltage signal to produce a first positive DC signal;

rectifying the first current signal to produce a first negative DC signal; and

summing the first positive DC signal and the first negative DC signal to produce the magnitude DC voltage indicator signal.

16 . The method of claim 14 , wherein the creating of the phase DC voltage indicator signal comprises:

shifting the second voltage signal relative to the second current signal to create a shifted voltage signal;

decomposing the second current signal into a shifted current signal and an unshifted current signal, the shifted current signal being shifted by 90 degrees;

adding the unshifted current signal to the shifted voltage signal to produce a first phase signal;

adding the shifted current signal to the shifted voltage signal to produce a second phase signal;

rectifying the first and second phase signal; and

summing the first and second phase signal to produce the phase DC Voltage indicator signal.

17 . The method of claim 14 , further comprising:

digitizing both the magnitude DC voltage indicator signal and the phase DC voltage indicator signal; and

applying a phase algorithm to the phase DC voltage indicator signal, and a magnitude algorithm to the magnitude DC voltage indicator signal, the phase algorithm and magnitude algorithm being linearly independent of each other.

18 . The method of claim 14 , where:

the adjusting of the phase capacitor comprises changing a phase position of the phase capacitor to a new phase position, thereby changing a phase capacitance of the phase capacitor; and

the adjusting of the load capacitor comprises changing a load position of the load capacitor to a new load position, thereby changing a load capacitance of the load capacitor.

19 . The method of claim 18 , where:

the new phase position is calculated by the following equation:

a current phase capacitor position added to a phase DC voltage indicator signal multiplied by a phase gain; and

the new load position is calculated as a current load capacitor position added to a magnitude DC voltage indicator signal multiplied by a magnitude gain.

20 . The system of claim 1 , wherein the impedance is tuned in real time such that the matching network can be placed an arbitrarily selected distance from a power source and near enough to an atmospheric pressure plasma creation device powered by the power source to allow for efficient dynamic minimization of the impedance.