| US 7,466,143 B2 | ||
| Clearance measurement systems and methods of operation | ||
| Emad Andarawis Andarawis, Ballston Lake, N.Y. (US); Richard Louis Frey, Delanson, N.Y. (US); and Samhita Dasgupta, Niskayuna, N.Y. (US) | ||
| Assigned to General Electric Company, Niskayuna, N.Y. (US) | ||
| Filed on Sep. 16, 2005, as Appl. No. 11/229,251. | ||
| Prior Publication US 2007/0222459 A1, Sep. 27, 2007 | ||
| Int. Cl. G01R 27/04 (2006.01) | ||
| U.S. Cl. 324—644 [324/646; 324/662] | 28 Claims |
| 1. A method comprising:
exciting a sensor with an incident signal;
generating a reflected signal by reflecting the incident signal from the sensor, wherein the incident signal and the reflected
signal interfere to form a standing wave;
processing the signals to determine a sensed parameter based upon a frequency at which the standing wave exhibits a null,
wherein processing the microwave signals comprises determining a lowest value of an amplitude of the standing wave; and
varying a frequency of the incident signal supplied to the sensor until the standing wave exhibits the null, wherein the processing further comprises:
generating a feedback signal based on a comparison between the lowest value and the null; and
controlling the frequency of the incident signal supplied to the sensor in response to the feedback signal to minimize a difference
between the lowest value and the null.
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