Patent ID: 7285963

Claim:
A method of measurement of a dielectric constant of a sample under study, comprising the steps of: (a) positioning the tip of a near-field microwave probe (NMP) a predetermined tip-sample separation distance over the surface of the sample under study, said NMP forming a resonator structure, (b) measuring probe resonant frequency shift ΔF ef =F e −F f vs. said tip-sample separation, wherein F e is the probe resonance frequency of an empty resonator structure, and F f is the probe resonance frequency measured at said predetermined tip-sample separation distance of said probe tip and said sample under study, (c) calibrating said near-field microwave probe for a plurality of calibration samples, each said calibration sample having a respective dielectric constant k c , by measuring probe resonant frequency shift ΔF ec =F e −F c vs. a distance between said probe tip and said each of said plurality of calibration samples, wherein F e is the probe resonance frequency of said empty resonator structure, and F c is the probe resonant frequency measured at said distance between said probe tip and said each calibration sample held substantially equal to said predetermined tip-sample separation, (d) constructing a calibration curve ΔF ec vs. γ=(k c −1)/(k c +1) based on calibration data points acquired as the result of the calibrating of said near-field microwave probe for said plurality of calibration samples, (e) fitting said probe resonant frequency shift ΔF ef of said sample under study into said calibration curve; and (f) extracting the dielectric constant k s of said sample under study therefrom.