Design, characterization, and application of metamaterial using high dielectric resonators

Cubic high dielectric resonator (CHDR) metamaterial is proposed as a new negative refractive index material. This purely dielectric metamaterial avoids three major drawbacks of metal-based metamaterials: scaling issues, conductor loss, and complexity in structure. CHDR metamaterial shows the negative refractive index (NRI) characteristic around the resonant frequencies of CHDR. The combination of the Mie resonances of the cube and the Bragg scattering and interference leads to the negative refractive index behavior. Strong displacement currents occur inside the cubic high dielectric resonator due to the resonance at its first resonance, a magnetic dipole is induced by these currents, and the periodic placement of the cubes creates the negative index in the frequency band at this resonance.; This structure was simulated using a finite difference time domain program to obtain the band diagram which shows the existence of the negative index behavior. Further simulations were performed using a finite element program to extract the effective permittivity and permeability, and also the negative refractive index regions of the structure. Three parameters, the orientation of the incident beam, the dielectric constant of cubes, and the lattice constant of the structure were investigated. These parameters were varied to determine the variation of the frequency range and magnitude of the negative refractive index regions.; As one of possible metamaterial applications, CHDR metamaterial was applied to antennas as a flat lens to improve the gain of antennas. Through numerical simulations and measurements, it was verified that high gain narrower beam may be obtained by using this flat lens.