A new free-space technique for measuring the complex permittivity and thickness of materials

A novel free-space method for the measurement of complex permittivity and thickness of materials has been developed. Antenna-medium coupling is taken into account. Thus, the antenna can be placed in close proximity to the sample material. Compared with conventional free-space techniques, the proposed method achieves a higher accuracy and it can be used in the UHF frequency range. An example is provided to demonstrate the performance of the method using simulated data.