Multi-band meta-material structures based on hexagonal shaped magnetic resonators

In the present paper, we propose a new multi band metamaterial structure composed of a unit cell that has multiple hexagonal-shaped metal rings printed one inside the other. The introduced metamaterial composition exhibits multi-resonant behavior due to distinct magnetic resonances caused by the self and mutual couplings of each inclusion. The number of distinct magnetic resonances is determined by the number of hexagonal-shaped rings placed in the unit cell. Using three rings in this paper, three distinct resonance frequencies can be shifted to desired values simply by changing the design parameters. Transmission and reflection spectra of the proposed structure are obtained using the CST Microwave Studio to observe its resonance frequencies. Then, the effective permeability and effective permittivity are retrieved from the already computed complex S-parameters to demonstrate the presence of three distinct negative permeability bandwidths.