Multi-band sub wavelength magnetic reflectors based on spiral

We report our experimental and theoretical studies on a metamaterials consisting of a metallic planar spiral with a metallic ground separated by a thin dielectric layer. We show that this structure, which is of isotropic with multi-band, can reflect electromagnetic wave in-phase at a series of frequencies and of subwavelength size at some lower resonance frequencies. This phenomenon is mainly governed by a series of holistic magnetic resonances.