Radio frequency power delivery system

• US 8,633,782 B2
• Filed: 05/25/2010
• Issued: 01/21/2014
• Est. Priority Date: 10/31/2005
• Status: Active Grant

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: Nagarkatti, Siddharth P., Kishinevsky, Michael, Shajii, Ali, Kalvaitis, Timothy E., McKinney, William S. Jr., Goodman, Daniel, Holber, William M., Smith, John A.
• Primary Examiner(s): Le, Tung X
• Application Number:
  US12/786,763
• Publication Number:
  US 20100231296A1
• Time in Patent Office: 1,337 Days
• Field of Search: 315/111.21, 333/17.3, 333/32, 118/712, 118/723.E, 156/345, 156/44, 156/28, 438/9
• US Class Current: 333/17.3
• CPC Class Codes: H03F 1/56 Modifications of input or output impedances, not otherwise provided for
• CPC Class Codes: H03F 3/191 Tuned amplifiers H03F3/193, H03F3/195 take precedence
• CPC Class Codes: H03F 3/20 Power amplifiers, e.g. Class B amplifiers, Class C amplifiers H03F3/26 - H03F3/30 take precedence

Abstract

A system and method are provided for delivering power to a dynamic load. The system includes a power supply providing DC power having a substantially constant power open loop response, a power amplifier for converting the DC power to RF power, a sensor for measuring voltage, current and phase angle between voltage and current vectors associated with the RF power, an electrically controllable impedance matching system to modify the impedance of the power amplifier to at least a substantially matched impedance of a dynamic load, and a controller for controlling the electrically controllable impedance matching system. The system further includes a sensor calibration measuring module for determining power delivered by the power amplifier, an electronic matching system calibration module for determining power delivered to a dynamic load, and a power dissipation module for calculating power dissipated in the electrically controllable impedance matching system.

Claims

1. A system for delivering power to a dynamic load, comprising:

a power supply providing DC power having a substantially constant power open loop response;

a power amplifier for converting the DC power to RF power, the power amplifier having a frequency set point;

a sensor for measuring voltage, current and phase angle between voltage and current vectors associated with the RF power;

an electrically controllable impedance matching system to modify the impedance of the power amplifier to at least substantially match an impedance of a dynamic load; and

a controller comprising;

a) a frequency control loop for controlling the frequency set point of the power amplifier based on a comparison of a conductance set point with a conductance value that is measured between the power amplifier and the dynamic load, and

b) an impedance control loop that controls the electrically controllable impedance matching network such that susceptance and not conductance changes between the power amplifier and the dynamic load when the impedance of the power amplifier changes.

2. The system of claim 1, wherein the controller controls the electrically controllable impedance matching system for simultaneous control of conductance and susceptance associated with the impedance between the power amplifier and the dynamic load.

3. The system of claim 1, wherein the electrically controllable impedance matching system comprises an inductor, a capacitor in series with the inductor, and a plurality of switched capacitors in parallel with the dynamic load.

4. The system of claim 3, wherein the inductor is a multiple tap-type inductor or a variable-type inductor.

5. The system of claim 3, wherein each of the plurality of switched capacitors is in series with a switch and an additional capacitor.

6. The system of claim 1, wherein the electrically controllable impedance matching system comprises a capacitor, and a plurality of switched capacitors in parallel with the dynamic load, wherein each of the plurality of capacitors is in series with a switch and an additional capacitor.

7. The system of claim 1, wherein the controller simultaneously controls RF power frequency, RF power magnitude and the impedance between the power amplifier and the dynamic load.

8. The system of claim 1, wherein the electrically controllable impedance matching system controls the frequency of the impedance matching between the power amplifier and the dynamic load.

9. The system of claim 1, wherein the controller controls the electrically controllable impedance matching system for regulating conductance and susceptance to setpoints that stabilize an unstable dynamic load.

10. A method for delivering power to a dynamic load, comprising:

providing DC power having a substantially constant power open loop response;

converting the DC power to RF power through a power amplifier, the power amplifier having a frequency set point;

measuring voltage, current and phase angle between voltage and current vectors associated with the RF power through a sensor; and

modifying the impedance of the power amplifier to at least substantially match an impedance of a dynamic load with an electrically controllable impedance matching system such that only susceptance and not conductance changes between the power amplifier and the dynamic load when the impedance of the power amplifier changes; and

controlling the frequency set point of the power amplifier based on a comparison of a conductance set point with a conductance value that is measured between the power amplifier and the dynamic load.

11. The method of claim 10, further comprising simultaneously controlling conductance and susceptance associated with the impedance between the power amplifier and the dynamic load.

12. The method of claim 10, further comprising simultaneously controlling RF power frequency, RF power magnitude and the impedance between the power amplifier and the dynamic load.

13. The method of claim 10, further comprising controlling the frequency of the impedance matching between the power amplifier and the dynamic load.

14. The method of claim 10, further comprising controlling the electrically controllable impedance matching system for regulating conductance and susceptance to setpoints that stabilize an unstable dynamic load.

15. The method of claim 10, further comprising calibrating the sensor into a resistive load.

16. The method of claim 10, further comprising calibrating an output of the electrically controllable impedance matching system into a load simulator.

17. A system for delivering power to a dynamic load, comprising:

means for providing DC power having a substantially constant power open loop response;

means for converting the DC power to RF power through a power amplifier, the power amplifier having a frequency set point;

means for measuring voltage, current and phase angle between voltage and current vectors associated with the RF power through a sensor; and

means for modifying the impedance of the power amplifier to at least substantially match an impedance of a dynamic load with an electrically controllable impedance matching system;

means for controlling the frequency set point of the power amplifier based on a comparison of a conductance set point with a conductance value that is measured between the power amplifier and the dynamic load, and

means for controlling the electrically controllable impedance matching network such that susceptance and not conductance changes between the power amplifier and the dynamic load when the impedance the power amplifier changes.