Microwave modeling and characterization of metamaterials and uniaxial composites

A novel approach for the electromagnetic modeling and characterization of metamaterials and advanced composites in the microwave band is presented. The modeling approach is based on the concept of a properly defined unit cell, which is simulated and optimized for a particular structure using the full wave electromagnetic field simulator in order to obtain the reflection and transmission coefficients in the specified frequency band. The characterization involves the determination of the effective dielectric and magnetic properties of the test sample corresponding to the particular unit cell in terms of the scattering coefficients using the proposed method. The characterization is first carried out with the help of simulated data, and then a number of metamaterials and composite structures are fabricated. The scattering coefficients of these fabricated structures are measured with the help of a vector network analyzer by fitting them precisely into a section of X-band rectangular waveguide, and the effective dielectric and magnetic properties of these samples are determined from the measured scattering coefficients using the proposed method. A comparison is made between the simulated and the experimental results, and any difference between the actual and the determined values is properly analyzed.