New Method to Estimate the Permittivity of Dielectric Materials Using MSPS

A new method to estimate the relative dielectric permittivity of material's sheet is presented. In this method, a conventional microstrip patch sensor (MSPS) is utilized to resonate at 2.45 GHz. An unknown material, considered as a superstrate layer of 5 mm thickness, is located in the near-field region of the MSPS, at a distance of 5 mm above the sensor. From the changes in the MSPS's parameters, the dielectric property of the unknown material can be deduced. Based on the conformal map theory, theoretical analyses were performed, and hence, simulation analyses were done using the CST-MW software package. This proposed method was validated through measurements. From the theoretical, simulation, and measurement results, it was shown that depending on the frequency response, the relative permittivity can be estimated.