In previous work, we derived generalized sheet-transition conditions (GSTCs) for the average electromagnetic fields across a metafilm, which, when properly designed, can have certain desired reflection and transmission properties. A metafilm is the two-dimensional equivalent of a metamaterial, and is essentially a surface distribution of electrically small scatterers characterized by electric and magnetic polarization densities. This GSTC has been used to calculate the reflection and transmission coefficients of the metafilm, where it is shown that reflection and transmission properties of the metafilm are expressed in terms of the electric and magnetic polarizabilities of the scatterers themselves. Conditions on these polarizabilities of the scatterers required to obtain total transmission and/or total reflection are obtained. These conditions can require either the electric or magnetic polarizability to become negative (analogous to negative-index metamaterials). By controlling the polarization densities of the scatterers in the metafilm, a ``smart'' and/or ``controllable'' surface can be realized. In this paper we will present both analytic and measurement results to demonstrate the realization of a controllable (``smart surface'') metafilm composed of resonant magnetodielectric particles. To this end, we present analytical results for plane-wave incident and waveguide measurements of the reflection and transmission properties of a controllable metafilm composed of spherical magneto-dielectric (yttrium iron garnet or YIG) particles. The good correlations between the measured and analytical results of the reflection and transmission characteristics of the metafilm demonstrated here indicated that it is possible to realize a controllable metafilm ('smart surface') composed of YIG spherical particles.
Citation: IEEE Transactions on Antennas and Propagation
Pub Type: Journals
metafilm, metamaterial, polarization, smart controllable surface, measured reflection and transmission properties