Ceramic sensors for wireless sensing

1. A RF resonator for sensing a physical or an environmental parameter, comprising:

a substrate having a substrate surface, and

a polymer-derived ceramic (PDC) element positioned on or within said substrate surface, wherein said RF resonator has a resonant frequency that changes as a function of said physical or said environmental parameter.

2. The RF resonator of claim 1 , wherein a quality (Q) factor of said RF resonator is ≧100.

3. The RF resonator of claim 1 , wherein a nominal resonant frequency of said RF resonator is between 1 and 40 GHz.

4. The RF resonator of claim 1 , further comprising a coupling structure including a planar antenna on or above said substrate surface for coupling RF energy to and from said RF resonator.

5. The RF resonator of claim 4 , wherein said RF resonator comprises an evanescent-mode pressure sensitive resonator, and said substrate having said substrate surface further comprises a cavity formed in said substrate, and said RF resonator further comprises a flexible top plate on said cavity, and said PDC element comprises at least one metal coated PDC post within said cavity, said evanescent-mode resonator having a pressure sensitive resonant frequency that changes as a gap between said PDC post and said top plate changes,

and said coupling structure further comprises a slot formed in said flexible top plate.

6. The RF resonator of claim 1 , wherein said RF resonator comprises an evanescent-mode pressure sensitive resonator, and said substrate having said substrate surface further comprises a cavity formed in said substrate, said RF resonator further comprises a flexible top plate on said cavity, and said PDC element comprises at least one metal coated PDC post within said cavity, said evanescent-mode resonator having a pressure sensitive resonant frequency that changes as a gap between said PDC post and said top plate changes.

7. The RF resonator of claim 6 , wherein said PDC element includes a metal coating and a dielectric coating on said metal coating that prevents oxidation of said metal.

8. The RF resonator of claim 1 , wherein said RF resonator comprises a temperature sensitive resonator and said PDC element comprises a dielectric resonator (DR) that has a temperature sensitive dielectric constant on said substrate surface.

9. The RF resonator of claim 8 , wherein said substrate comprises a ceramic substrate.

10. The RF resonator of claim 1 , wherein said PDC element comprises SiAlCN, SiCN or SiBCN.

11. A system for wirelessly sensing at least one physical or environmental parameter, comprising:

at least one RF resonator for sensing said physical or said environmental parameter comprising:

a substrate having a substrate surface, and

a polymer-derived ceramic (PDC) element positioned on or within said substrate surface, wherein said RF resonator has a resonant frequency that changes as a function of said physical or said environmental parameter, and

a wireless RF reader located remotely from said RF resonator, said wireless RF reader for transmitting a wide-band RF interrogation signal that excites said RF resonator, wherein said wireless RF reader detects a sensing signal retransmitted by said RF resonator and includes a processor for determining said physical or environmental parameter at a location of said RF resonator.

12. The system of claim 11 , wherein a nominal resonant frequency of said RF resonator is between 1 and 40 GHz.

13. The system of claim 11 , further comprising a coupling structure including a planar antenna on or above said substrate surface for coupling RF energy to and from said RF resonator.

14. The system of claim 11 , wherein said RF resonator comprises an evanescent-mode pressure sensitive resonator, and said substrate having said substrate surface further comprises a cavity formed in said substrate, said RF resonator further comprises a flexible top plate on said cavity, and said PDC element comprising at least one metal coated PDC post within said cavity, said evanescent-mode resonator having a pressure sensitive resonant frequency that changes as a gap between said PDC post and said top plate changes.

15. The system of claim 14 , wherein said PDC element includes a metal coating and a dielectric coating on said metal coating that prevents oxidation of said metal.

16. The system of claim 11 , wherein said RF resonator comprises an evanescent-mode pressure sensitive resonator, and said substrate having said substrate surface further comprises a cavity formed in said substrate, and said RF resonator further comprises a flexible top plate on said cavity, and said PDC element comprises at least one metal coated PDC post within said cavity, said evanescent-mode resonator having a pressure sensitive resonant frequency that changes as a gap between said PDC post and said top plate changes,

and said coupling structure further comprises a slot formed in said flexible top plate.

17. The system of claim 11 , wherein said RF resonator comprises a temperature sensitive resonator and said PDC element comprises a dielectric resonator (DR) that has a temperature sensitive dielectric constant on said substrate surface.

18. The system of claim 11 , wherein said PDC element comprises SiAlCN, SiCN or SiBCN.

19. The system of claim 11 , wherein said at least one RF resonator comprises a plurality of said RF resonators, said plurality of said RF resonators bonded to different locations within said system.

20. The system of claim 19 , wherein said plurality of said RF resonators each provide different resonant frequencies.

21. The system of claim 11 , wherein said system comprises a turbine engine comprising a turbine blade, and wherein said RF resonator is bonded to said turbine blade.

22. A method of forming an RF resonator for sensing a physical or an environmental parameter, comprising:

providing a substrate comprising a substrate surface having a polymer-derived ceramic (PDC) precursor within or thereon;

lithographically defining at least one element comprising said PDC precursor, and

converting said element into a PDC element,

wherein said RF resonator has a resonant frequency that changes as a function of said physical or said environmental parameter.

23. The method of claim 22 , wherein said converting comprises pyrolysis.

24. The method of claim 22 , further comprising the step of modifying said PDC precursor by adding monomers comprising vinyl groups before said lithographically forming.

25. The method of claim 22 , wherein said RF resonator comprises an evanescent-mode pressure sensitive resonator, and said lithographically forming further comprises forming a cavity in said substrate, wherein said PDC element is within said cavity, further comprising:

forming a flexible top plate;

bonding said flexible top plate onto said cavity.

26. The method of claim 22 , wherein said RF resonator comprises a temperature sensitive resonator and said PDC element comprises a dielectric resonator (DR) that has a temperature sensitive dielectric constant on said substrate surface.

27. The method of claim 22 , wherein said PDC element comprises SiAlCN, SiCN or SiBCN.