Retrieval of effective constitutive parameters for biaxial bianisotropic metamaterials using reference-plane-invariant waveguide method

This study is about electromagnetic characterization of bi-axial bianisotrpic metamaterials. Rectangular waveguide method is used to extract scattering parameters in microwave X-band frequency region. In general, by these techniques it is presumed that the measurement and reference planes of specimen are overlapped which can cause errors otherwise. Reference-plane-invariant technique is investigated for the extraction of the effective constitutive parameters. By this technique, the measurements, can be performed without precise knowledge of the positions of the measured specimen reference planes. The study is validated by comparing extracted constitutive parameters with a method requiring reference plane position of the measured slab. As a preliminary, the concept is simulated by a commercial electromagnetic field simulation software. The results obtained by simulations are reinforced with physical waveguide experiments by using a vector network analyzer. For the measurement experiments, split-ring-resonator type metamaterials are designed, fabricated and used.