Multipoint voltage and current probe system

• US 8,055,203 B2
• Filed: 06/14/2007
• Issued: 11/08/2011
• Est. Priority Date: 03/14/2007
• Status: Active Grant

• Current Assignee: MKS Instruments Incorporated
• Original Assignee: MKS Instruments Incorporated
• Inventors: Choueiry, Ray, Heckleman, Todd, Coumou, David J.
• Primary Examiner(s): Nguyen; Simon
• Application Number:
  US11/763,298
• Publication Number:
  US 20080227420A1
• Time in Patent Office: 1,608 Days
• Field of Search: 455/41.1, 455 6711- 6712, 455/226.1, 455/226.2, 455/115.1, 455/115.3, 4551271-1274, 315/111.21
• US Class Current: 455/67.11
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H04B 17/318 Received signal strength

Abstract

A metrology system monitors radio frequency (RF) power at a plurality of locations in a circuit. The system includes a plurality of RF sensors that generate respective analog signals based on electrical properties of the RF power, a multiplexing module that generates an output signal based on the analog signals, and an analysis module that generates messages based on the output signal. The messages contain information regarding the electrical properties that are sensed by the plurality of RF sensors.

Claims

1. A metrology system for monitoring radio frequency (RF) power at a plurality of locations in a circuit, comprising:

a plurality of sense channels that each generate an output signal based on an electrical property of the RF power at one of the locations in the circuit, each sense channel comprising;

a RF sensor that generates a first signal based on the electrical property of the RF power;

an oscillator that generates a periodic signal; and

a mixer that mixes the first signal with the periodic signal to generate the output signal for the sense channel; and

a RF combiner that generates a second output signal based on the plurality of output signals from the sense channels.

2. The metrology system of claim 1 further comprising:

an analysis module that generates messages based on the second output signal from the RF combiner, wherein the messages contain information regarding the electrical properties that are sensed by the plurality of sense channels.

3. The metrology system of claim 1 wherein the RF sensor is a directional coupler.

4. The metrology system of claim 1 wherein the RF sensor is a voltage/current (V/I) probe.

5. The metrology system of claim 1 further comprising a plurality of low pass filters that filter respective ones of the first signals from the RF sensors.

6. The metrology system of claim 1 further comprising a plurality of high pass filters that filter respective ones of the output signals from the sensor channels.

7. The metrology system of claim 1 further comprising a filter that filters the second output signal from the RF combiner.

8. The metrology system of claim 1 wherein each of the periodic signals has a frequency that is different from the other periodic signals.

9. The metrology system of claim 8 wherein the frequencies are evenly-spaced in the frequency domain.

10. A metrology system for monitoring radio frequency (RF) power at a plurality of locations in a circuit, comprising:

a plurality of sense channels that each generate a pair of output signals based on electrical properties of the RF power at one of the locations in the circuit, each sense channel comprising;

a RF sensor that generates a pair of analog signals based on the RF power;

an oscillator that generates first and second periodic signals that are out-of-phase;

a first mixer that mixes the first periodic signal with one of the analog signals to generate one of the output signals of the sense channel; and

a second mixer that mixes the second periodic signal with the other one of the analog signals to generate a second one of the output signals of the sense channel;

a first RF combiner that generates a first broadband signal based on the plurality of output signals from the first mixers; and

a second RF combiner that generates a second broadband signal based on the plurality of output signals from the second mixers.

11. The metrology system of claim 10 further comprising:

an analysis module that generates messages based on the broadband signals from the first and second RF combiners, wherein the messages contain information regarding the electrical properties that are sensed by the plurality of sense channels.

12. The metrology system of claim 10 wherein the RF sensors are directional couplers.

13. The metrology system of claim 10 wherein the RF sensors are voltage/current (V/I) probes.

14. The metrology system of claim 10 further comprising low pass filters that filter respective ones of the analog signals from the RF sensors.

15. The metrology system of claim 10 further comprising a plurality of high pass filters that filter respective ones of the output signals from the sensor channels.

16. The metrology system of claim 10 further comprising first and second filters that filter respective ones of the first and second broadband signals.

17. The metrology system of claim 10 wherein each of the periodic signals has a frequency that is different from the other periodic signals.

18. The metrology system of claim 17 wherein the periodic signal frequencies are evenly-spaced in the frequency domain.

19. A method for monitoring radio frequency (RF) power at a plurality of locations in a circuit, comprising:

generating an output signal based on an electrical property of the RF power at an associated one of the locations in the circuit, each generating step including;

generating a first signal based on the RF power;

generating a periodic signal; and

mixing the first signal with the periodic signal to generate the output signal; and

combining the output signals to generate a broadband signal that includes frequency components of each of the output signals.

20. The method of claim 19 further comprising generating messages based on the broadband signal, wherein the messages contain information regarding the electrical properties.

21. The method of claim 19 wherein the electrical property includes at least one of forward power and reflected power.

22. The method of claim 19 wherein the electrical property includes at least one of voltage and current.

23. The method of claim 19 further comprising filtering the first signals.

24. The method of claim 19 further comprising filtering the output signals.

25. The method of claim 19 further comprising filtering the broadband signal from the RF combiner.

26. The method of claim 19 wherein each of the periodic signals has a frequency that is different from the other periodic signals.

27. The method of claim wherein the frequencies are evenly-spaced in the frequency domain.