Experimental Characterization of Positive and Negative Dielectric Constants and Artificial Anisotropy of Meta-materials in the Microwave Range

Abstract

Abstract This paper could be considered as a part of the invited talk “Metamaterials and Their Characterization in the Microwave Range” presented on the 8th International Workshop and Summer School on Plasma Physics (IWSSPP’2018, Kiten, Bulgaria), which has been dedicated to the classification, development, characterization and main applications of the metamaterials as one of the key issues of the modern technologies in the microwave, terahertz and optical regions. The experimental characterization of the actual equivalent dielectric parameters of the engineered artificial metamaterials is an important task in their design, nevertheless the existing relatively good correlation between the numerical simulations of these materials by 3D simulators and their measurements. The aim of the presented investigations is to give a helpful comparison between the most popular characterization methods based on free-space, waveguide and resonance measurements in the microwave range. The description of these methods has been based on the following principle: different metamaterials with surface metal inclusions have been selected and their main characteristics – equivalent dielectric constants in different directions (dielectric anisotropy) and the equivalent conductivity have been compared. A special attention has been directed to the description of measurements of positive and negative values of the permittivity, detection of artificial magnetic properties and resonance behaviour of the conductivity of the considered metamaterials.