Measurements of planar metal-dielectric structures using split-post dielectric resonators

Abstract

Split-post dielectric resonators were used for the measurement of the complex permittivity and the complex permeability of planar, uniaxialy anisotropic, low- and medium-loss metamaterials at microwave frequencies. Several metamaterials with different metal patterns deposited on dielectric substrates by plasma deposition were investigated, including edge-coupled and broadside-coupled split-rings and circles. It has been shown that, depending on the type of metal pattern and their surface resistance, the metamaterials may exhibit various magnetic and dielectric properties. Several small metamaterial samples were scanned in the cavity electromagnetic field by moving them inside the split-post dielectric resonator. This allowed us to identify loss mechanisms in the samples and to distinguish between their electric and magnetic properties. Our measurements were confirmed by modeling the transmission/reflection characteristics of virtual waveguides containing real metamaterial samples and homogenous samples with the same effective electromagnetic properties as those obtained from the split-post dielectric resonator method using a finite-difference time-domain electromagnetic simulator software package.