Measurements of the complex permittivity and the complex permeability of low and medium loss isotropic and uniaxially anisotropic metamaterials at microwave frequencies

Abstract

Split dielectric resonators operating in a quasi-TE011 mode were used for the measurement of the complex permittivity and the complex permeability of planar metamaterials deposited on low-loss dielectric substrates at microwave frequencies. Separation of the complex permittivity from the complex permeability for a specific metamaterial was achieved by performing measurements of the resonance frequencies and the Q-factors of a split post-dielectric resonator with two samples having different diameters but identical patterns. Measurements of the resonance frequencies and the Q-factors of empty substrates served as reference materials to determine the resonance frequency shifts and Q-factor changes due to the presence of the metamaterial only. The effective complex permittivity and permeability were determined on the basis of accurate electromagnetic modeling of the resonance structures containing the samples.

Measurements of the complex permittivity of highly concentrated aqueous NaCl solutions and ferrofluid employing microwave cylindrical cavities

“…As a result, at microwave frequencies ferrofluid behaves like diamagnetic material. Similar properties are observed in solid metamaterials containing metallic islands or rings [16]. It should also be noted that the magnetic losses of ferrofluid are larger than the dielectric losses.…”

“…The simultaneous use of two resonators that resonate at similar frequencies but on different modes or measurements of the sample at two different positions in one resonator allow determination of both the complex permittivity and the complex permeability of the sample. Such a method has been used for measurements of the permeability tensor of microwave ferrites [15] and also of the dielectric and magnetic properties of metamaterials [16]. For liquid samples the most convenient choice is to employ two cylindrical cavities having such dimensions that they operate at similar frequencies, one on the TM010 mode and the other on the TE011 mode.…”

Experimental study of thermally controlled metamaterial containing a liquid crystal layer at microwave frequencies

“…However, for samples with low surface resistance the maximum dissipated power corresponds to the maximum of the normal component of the magnetic field in the cross-section of the SPDR, which is along the resonator axis [6].…”

Measuring the dielectric properties of materials. Ninety-year development from low-frequency techniques to broadband spectroscopy and high-frequency imaging

“…Under such conditions, resonance techniques are again preferred and are facilitated by network analyser technology that allows for fast, easy and accurate scanning of resonance curves. Promoted by the demands in special applications, various resonator constructions have been developed in the past years, among them split-ring [382,383], split-post [384][385][386][387], dielectric [238,388,389] and dielectric split-post [390] resonators, as well as whispering gallery dielectric resonators [391][392][393][394].…”