Wireless sensing and communication utilizing RF transmissions from microdischarges

• US 20060264175A1
• Filed: 05/17/2005
• Published: 11/23/2006
• Est. Priority Date: 05/17/2005
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Gharpurey, Ranjit, Eun, Christine K., Gianchandani, Yogesh B.
• Granted Patent: US 9,083,392 B2
• Time in Patent Office: Days
• US Class Current: 455/41.100
• CPC Class Codes: H04B 5/73 for taking measurements, e.g. using sensing coils

Abstract

Disclosed herein are systems and devices capable of wireless communications based on RF transmissions from discharges. A transmitting device includes a discharge generator having a plurality of electrodes spaced to support generation of the discharge, and a circuit coupled to the plurality of spaced electrodes to control a supply for the discharge generator. In some embodiments, controlling the supply for the discharge generator modifies a property of the discharge to modulate the RF transmission such that the resulting RF transmission is indicative of the device state or other information to be communicated.

Claims

1. A system capable of RF communication, the system comprising:

a device comprising a plurality of microfabricated electrodes spaced to support generation of a microdischarge, wherein an RF transmission is generated by the microdischarge; and

,

an antenna to receive the RF transmission from the microdischarge to enable the RF communication.

2. The system of claim 1, wherein the device comprises a sensor having a state such that the RF transmission generated by the microdischarge is indicative of the sensor state.

3. The system of claim 2, wherein the sensor comprises the microfabricated electrodes.

4. The system of claim 3, wherein the sensor indicates whether a chemical species is present via a modification of a characteristic of the RF transmission resulting from an interaction between the microdischarge and the chemical species.

5. The system of claim 4, wherein the sensor indicates whether a further chemical species is present via a further modification of the characteristic of the RF transmission resulting from an interaction between the microdischarge and the further chemical species, and wherein the first-named and further modifications of the RF transmission characteristic are different.

6. The system of claim 3, wherein the plurality of microfabricated electrodes comprises an electrode pair and a high-impedance gate electrode having a voltage applied thereto to facilitate the microdischarge between the electrode pair.

7. The system of claim 3, wherein the sensor state is responsive to a beta particle interaction with the sensor such that the RF transmission is indicative of whether a beta particle has been detected.

8. The system of claim 2, wherein the sensor comprises a structure comprising one of the microfabricated electrodes and having a position movable in response to an external force to be detected by the sensor.

9. The system of claim 8, wherein the structure comprises a suspended beam having a discharge tip such that the sensor comprises an accelerometer.

10. The system of claim 1, wherein the device comprises a power source, a microdischarge generator comprising the plurality of microfabricated electrodes, and a sensor coupled to the power source and the microdischarge generator, such that a supply for the microdischarge generator is controlled by a transduction state of the sensor.

11. The system of claim 10, wherein the sensor comprises a passive element having a variable impedance to vary the supply for the microdischarge generator.

12. The system of claim 10, wherein the microdischarge generator comprises a boost converter coupled to the plurality of microfabricated electrodes.

13. The system of claim 1, wherein the device comprises one or more passive circuit elements coupled to the plurality of microfabricated electrodes to control the microdischarge for spectral shaping of the RF transmission.

14. The system of claim 1, further comprising a power detector coupled to the antenna.

15. The system of claim 1, further comprising a matched filter coupled to the antenna and configured to detect a predetermined pulse shape of the RF transmission.

16. The system of claim 1, wherein the device is one of an array of distributed devices of the system generating microdischarges, wherein the antenna receives respective RF transmissions from the device array, and wherein the system further comprises a monitoring device coupled to the antenna to monitor the respective RF transmissions individually.

17. The system of claim 16, wherein each device of the plurality of devices comprises a micro-electro discharge machining apparatus to machine a respective workpiece such that the monitoring device analyzes the respective RF transmission to monitor operation of the micro-electro discharge machining apparatus.

18. A device having a state, the device comprising:

a discharge generator comprising a plurality of electrodes spaced to support generation of a discharge; and

,

a circuit coupled to the plurality of spaced electrodes to control a supply for the discharge generator such that an RF transmission generated by the discharge is indicative of the state of the device.

19. The device of claim 18, wherein the state of the device reflects a circuit condition of the circuit that modifies the discharge such that a characteristic of the RF transmission is indicative of the state of the device.

20. The device of claim 19, wherein the circuit comprises a sensor such that the circuit condition is based on a sensed condition external to the circuit.

21. The device of claim 18, wherein the plurality of spaced electrodes comprises an electrode pair and a high-impedance gate electrode having a voltage applied thereto to facilitate the discharge between the electrode pair.

22. The device of claim 18, wherein a position of one of the plurality of electrodes is movable such that the discharge is generated across a variable gap having a spacing determinative of the state.

23. The device of claim 18, wherein the circuit comprises one or more circuit elements that vary the supply for the discharge generator in accordance with the state.

24. The device of claim 18, wherein the circuit comprises a passive element having a variable impedance to vary the supply for the discharge generator in accordance with the state.

25. The device of claim 18, wherein the circuit comprises a boost converter coupled to the plurality of electrodes to control the supply for the discharge generator.

26. The device of claim 18, wherein the circuit comprises one or more passive circuit elements coupled to the discharge generator for spectral shaping of the RF transmission.

27. A method of transmitting data from a device, the method comprising the steps of:

generating an RF transmission from a discharge between spaced electrodes of the device; and

,

modifying a property of the discharge to modulate the RF transmission such that the RF transmission is indicative of the data.

28. The method of claim 27, wherein the modifying step comprises controlling a supply for the discharge based on a variable circuit element of a circuit of the device coupled to the spaced electrodes.

29. The method of claim 28, wherein the variable circuit element is responsive to a condition external to the circuit such that the data is indicative of the condition.

30. The method of claim 27, wherein the modifying step comprises the step of generating a supply signal for the discharge that is indicative of the data.

31. The method of claim 30, wherein the supply signal comprises a frequency component indicative of the data.

32. The method of claim 30, wherein the supply signal generating step comprises the step of superimposing a current signal during the discharge.

33. The method of claim 27, wherein the modifying step comprises controlling a noise signature of the discharge such that the noise signature is indicative of the data.

34. The method of claim 27, further comprising the steps of:

receiving the RF transmission from the discharge; and

,

analyzing a frequency spectrum of the RF transmission to determine the data.

35. The method of claim 34, further comprising the step of filtering the received RF transmission to improve a signal-to-noise ratio thereof.

36. The method of claim 35, wherein the filtering step comprises utilizing a matched filter configured to detect a predetermined pulse shape.

37. A method of transmitting information from a device, the method comprising the steps of:

generating a discharge between spaced electrodes of the device;

receiving an RF transmission resulting from the discharge; and

,

analyzing a frequency spectrum of the RF transmission to determine the information.

38. The method of claim 37, wherein the device comprises a Geiger counter to detect whether a radioactive species is present, and wherein the analyzing step comprises detecting whether the frequency spectrum indicates that the radioactive species is present.

39. The method of claim 37, further comprising filtering the received RF transmission to improve a signal-to-noise ratio thereof.

40. The method of claim 39, wherein the filtering step comprises utilizing a matched filter configured to detect a predetermined pulse shape.

41. The method of claim 37, wherein the generating step comprises pre-filtering the RF transmission by modifying a property of the discharge.

42. A system capable of RF communication, the system comprising:

a plurality of devices, each respective device having a control circuit coupled to electrodes spaced to support a discharge to generate a corresponding RF transmission to carry data for the respective device; and

,

a receiver to monitor the plurality of devices via the corresponding RF transmissions.

43. The system of claim 42, wherein each respective device of the plurality of devices comprises an electro discharge machining apparatus to process a workpiece such that the electrode discharge machining apparatus comprises a first electrode and the workpiece comprises a second electrode spaced from the first electrode to support the discharge.

44. The system of claim 42, wherein each respective device of the plurality of devices comprises a sensor such that the data for the respective device is indicative of a sensed condition of the sensor.

45. The system of claim 42, further comprising a control device to generate a control signal for transmission to the control circuit of each respective device such that the discharge of each respective device is in accordance with information transmitted via the control signal.

46. The system of claim 45, wherein the receiver comprises the control device.

47. The system of claim 45, wherein the control signal comprises an RF transmission generated from a discharge between spaced electrodes of the control device.