Patent ID: 8760174

Claim:
A method of measuring an unknown property of a target material with an evanescent microwave microscopy probe, the method of measuring an unknown property comprising: adjusting a position of a probe tip of a microwave microscopy probe to a reference distance g from a target material, the microwave microscopy probe comprising a center conductor, an outer shield, an insulating material, and an aperture, wherein: the center conductor is at least approximately 90%, by weight, silver and is capable of operating as a waveguide for microwave radiation; a first end of the center conductor tapers to the probe tip capable of acquiring a near-field microwave signal from the target material; the outer shield surrounds the center conductor; the center conductor and the outer shield are in a generally coaxial relationship; the center conductor and the outer shield are not in direct contact such that a gap exists between the center conductor and the outer shield; the insulating material occupies at least a portion of the gap between the center conductor and the outer shield; the aperture is located near the probe tip and comprises a plate comprising an inside face, an outside face, and a hole having a diameter d that allows the probe tip to be in microwave communication with the target material; and the reference distance g is greater than the diameter d of the hole; taking a reference measurement of at least one inherent characteristic of the probe while the probe tip is at the reference distance g; adjusting the position of the probe tip such that the probe tip is in physical contact with the target material; taking a second measurement of the inherent characteristic while the probe tip is in physical contact with the target material; and determining the unknown property of the target material by comparing the reference measurement and the second measurement.