A three-dimensional (3D) finite element simulation was performed to model the behavior of the measuring resonator in an evanescent microwave probe (EMP). A calibration curve was derived using the frequency shift data as standards. The EMP measuring techniques was applied to measure the dielectric properties of Ba(Mg1/3Ta2/3)O3, BMT, materials. The average dielectric constants for these BMT materials (εr=26–30) are consistent with the dielectric properties measured by conventional cavity method. The EMP mapping indicates clearly the presence of higher or lower dielectric constant inclusions in the one-step processed BMT materials, which contain a large proportion of secondary phases. The measurements demonstrate that the EMP method is capable of mapping the distribution of dielectric constant at very high spatial resolution.
Journal of the European Ceramic Society 23(14), pp.2667-2670