| US 7,550,963 B1 | ||
| Analytical scanning evanescent microwave microscope and control stage | ||
| Xiao-Dong Xiang, Danville, Calif. (US); Chen Gao, Anhui (China); Fred Duewer, Albany, Calif. (US); Hai Tao Yang, Albany, Calif. (US); and Yalin Lu, Chelmsford, Mass. (US) | ||
| Assigned to The Regents of the University of California, Oakland, Calif. (US) | ||
| Filed on Jun. 30, 2000, as Appl. No. 9/608,311. | ||
| Application 09/608311 is a continuation in part of application No. 09/158037, filed on Sep. 22, 1998, granted, now 6,173,604. | ||
| Application 09/158037 is a continuation in part of application No. 08/717321, filed on Sep. 20, 1996, granted, now 5,821,410. | ||
| Claims priority of provisional application 60/141698, filed on Jun. 30, 1999. | ||
| Claims priority of provisional application 60/059471, filed on Sep. 22, 1997. | ||
| Int. Cl. G01R 27/00 (2006.01) | ||
| U.S. Cl. 324—158.1 [324/635] | 39 Claims |
| 5. A method for measuring electrical impedance of a sample using a microwave cavity probe, said microwave cavity probe comprising
a resonant microwave cavity having an aperture in an electrically conducting endwall and having a center conducting element
comprising a tip that extends through the aperture beyond the endwall, the method comprising:
positioning said sample outside said microwave cavity and adjacent said tip;
causing said tip to emit an evanescent electromagnetic field;
measuring a resonant frequency shift of said probe, wherein said resonant frequency shift results from interaction between
said sample and said evanescent electromagnetic field; and
determining said electrical impedance and the distance between said tip and said sample using the measured resonant frequency
shift.
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