Dual signal coaxial cavity resonator plasma generation

Patent metadata

Field	Value
Publication number	US-9873315-B2
Application number	US-201514680734-A
Country	US
Kind code	B2
Filing date	Apr 7, 2015
Priority date	Apr 8, 2014
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A plasma generator comprises a radio frequency power source, a coaxial cavity resonator assembly, and a direct current power source. The radio frequency power source provides a voltage supply of radio frequency power having a first ratio of power over voltage. The resonator assembly includes a center conductor coupled to the radio frequency power source, and also includes a virtual short circuit. The direct current power source is connected to the center conductor at the virtual short circuit, and provides a voltage supply of direct current power having a second ratio of power over voltage that is less than the first ratio.

First claim

What is claimed is:

1. A plasma generator comprising:
a source of radio frequency power;
a coaxial cavity resonator assembly including a center conductor that is both oriented in a coupling arrangement to the source of radio frequency power and is configured to maintain a voltage null at a first location; and
a source of direct current power connected to the center conductor proximal to the first location.

2. The plasma generator of claim 1 , further comprising:
a radio frequency control component connected between the source of direct current power and the coaxial cavity resonator assembly, and configured to restrict the passage of a voltage supply of radio frequency power to the source of direct current power.

3. The plasma generator of claim 2 , wherein the radio frequency control component is an additional resonator assembly configured to shift the voltage supply of radio frequency power 180 degrees out of phase relative to a ground plane of the coaxial cavity resonator assembly.

4. The plasma generator of claim 1 , wherein the coaxial cavity resonator assembly comprises a plurality of quarter wave coaxial cavity resonators coupled in a series arrangement, the resonators including center conductors coupled to the source of radio frequency power.

5. The plasma generator of claim 1 , further comprising:
a power source controller configured to direct the source of radio frequency power to provide a voltage supply of radio frequency power with a first ratio of power over voltage and configured to direct the source of direct current power to provide a voltage supply of direct current power with a second ratio of power over voltage, wherein the first ratio is greater than the second ratio.

6. A plasma generator comprising:
a radio frequency power source;
a coaxial cavity resonator assembly including a center conductor that is oriented in a coupling arrangement to the radio frequency power source and is configured to maintain a voltage null at a first location;
an open end discharge quarter wave coaxial cavity resonator including a center conductor having a proximal end coupled to the first location; and
a direct current power source connected proximal to the first location.

7. A plasma generator comprising:
a radio frequency power source configured to provide a voltage supply of radio frequency power having a first ratio of power over voltage;
a coaxial cavity resonator assembly including a center conductor that is oriented in a coupling arrangement to the radio frequency power source and is configured to maintain a voltage null at a first location; and
a direct current power source connected to the center conductor proximal to the first location and configured to provide a voltage supply of direct current power having a second ratio of power over voltage that is less than the first ratio.

8. A plasma generator comprising:
a radio frequency power source;
a coaxial cavity resonator assembly including a center conductor that is oriented in a coupling arrangement to the radio frequency power source and is configured to maintain a voltage null at a first location; and
a power source configured to provide a substantially constant voltage supply of direct current power to the coaxial cavity resonator assembly proximal to the first location.

9. An apparatus for generating a plasma under the influence of a threshold amount of voltage necessary to initiate a plasma, comprising:
a radio frequency power source configured to provide a voltage supply of radio frequency power with a first ratio of power over voltage;
a coaxial cavity resonator assembly including a center conductor that is oriented in a coupling arrangement to the radio frequency power source and is configured to maintain a voltage null at a first location; and
a direct current power source connected to the center conductor proximal to the first location and configured to provide a voltage supply of direct current power with a second ratio of power over voltage, and which together with the voltage supply of radio frequency power meets or exceeds the threshold voltage;
wherein the first ratio is greater than the second ratio.

10. The plasma generating apparatus of claim 9 , wherein the direct current power source is configured to operate in a mode which provides the voltage supply of direct current power as a substantially constant voltage supply of direct current power.

11. The plasma generating apparatus of claim 9 , further comprising:
a radio frequency control component connected between the direct current power source and the coaxial cavity resonator assembly, and configured to restrict the passage of the voltage supply of radio frequency power to the direct current power source.

12. The plasma generating apparatus of claim 11 , wherein the radio frequency control component is an additional resonator assembly configured to shift the voltage supply of radio frequency power 180 degrees out of phase relative to a ground plane of the coaxial cavity resonator assembly.

13. The plasma generating apparatus of claim 9 , further comprising:
a power source controller configured to direct the radio frequency power source and the direct current power source to provide a combined source of voltage that meets or exceeds the threshold voltage wherein the first ratio is greater than the second ratio.

14. An apparatus for generating a plasma under the influence of a threshold amount of voltage necessary to initiate a plasma, comprising:
a radio frequency power source configured to provide a voltage supply of radio frequency power;
a coaxial cavity resonator assembly including a center conductor that is oriented in a coupling arrangement to the radio frequency power source and is configured to maintain a voltage null at a first location;
a power source configured to provide a voltage supply of direct current power to the coaxial cavity resonator assembly at the first location, wherein the voltage supply of direct current power together with the voltage supply of radio frequency power meets or exceeds the threshold amount of voltage; and
wherein the power source is further configured to provide the voltage supply of direct current power in a range with a lower limit of about 51 percent and an upper limit less than 100 percent of the threshold amount of voltage.

15. The plasma generating apparatus of claim 14 , wherein the power source is configured to operate in a mode which provides the voltage supply of direct current power as a substantially constant voltage supply of direct current power.

16. The plasma generating apparatus of claim 14 , further comprising:
a radio frequency control component connected between the direct current power source and the coaxial cavity resonator assembly, and configured to restrict the passage of radio frequency power to the direct current power source.

17. The plasma generating apparatus of claim 16 , wherein the radio frequency control component is an additional resonator assembly configured to shift the voltage supply of radio frequency power 180 degrees out of phase relative to a ground plane of the coaxial cavity resonator assembly.

18. The plasma generating apparatus of claim 14 , further comprising:
a power source controller configured to direct the radio frequency power source to provide a voltage supply of radio frequency power with a first ratio of power over voltage and configured to direct the direct current power source to provide a voltage supply of direct current power with a second ratio of power over voltage, wherein the first ratio is greate

Assignees

• Plasma Igniter LLC
• Univ West Virginia

Inventors

• Spencer Michael J
• Lowery Andrew D
• Smith James E

Classifications

• H01J37/32247 Primary

  Resonators · CPC title

• F02P23/045

  using electromagnetic microwaves · CPC title

• H05H1/46

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) · CPC title

• F02P9/007

  by supplementary electrical discharge in the pre-ionised electrode interspace of the sparking plug, e.g. plasma jet ignition · CPC title

• F02P3/01 Primary

  Electric spark ignition installations without subsequent energy storage, i.e. energy supplied by an electrical oscillator (with magneto- or dynamo-electric generators F02P1/00; piezoelectric ignition F02P3/12; with continuous electric spark F02P15/10) · CPC title