Physical realization of magnetic walls using finite-thickness 3D printed arrays

Perfect magnetic conductors (PMC) have been useful in electromagnetics for many years as subsidiary hypothetical surfaces in conjunction with formal dualities between dielectric and magnetic currents and vector potentials. This in turn helped formulating equivalence theorems and solving many scattering problems involving either a single scatterer in a solvable background (aperture in waveguiding structures) or many scatterers in highly symmetrical distributions. Physically, however, natural material, used in microwave engineering had been macroscopically classified as (low-loss) dielectrics and (im)perfect electric conductors. The natural dispersive characteristics of these materials are rarely considered in microwave engineering, because they occur at far greater frequencies. We show that artificial metalo-dielectric crystals, composed of printed elements in a 3D array do exhibit magnetic conductor behavior, provided the size of the elements is a good fraction of the wavelength. In essence, we can think of the printed elements as artificial atoms seated up to microwave frequencies. The resulting medium is analogous to a natural metal at plasma frequencies (ultraviolet regime) where the latter also behaves like a magnetic conductor.