Mirror-symmetric double-negative metamaterial resonator with polarization insensitivity and tunable sandwiched structure for multiband wireless communications.

This paper presents a novel Double-negative (DNG) metamaterial (MM) resonator with a mirror-symmetric configuration, designed to exhibit multiband resonances in the S, C, and X bands. The resonator is fabricated using advanced processing techniques on a Rogers 5880 substrate and features electrodeposited copper. It consists of four equal regions, each containing interconnected split-ring resonators that are connected through a cross-shaped structure to ensure mirror symmetry. The simulation results demonstrate six resonance points at frequencies of 2.45 GHz, 4.27 GHz, 6.86 GHz, 8.98 GHz, 10.69 GHz, and 11.65 GHz. These resonances are characterized by near-zero/negative permeability, negative permittivity, refractive index, and impedance. Furthermore, the cross-polarization effect of incident waves is investigated. Additionally, the potential for tunability of resonance frequencies is explored through a sandwiched configuration of the MM resonator, achieved by modifying the cover of the resonating patch. Moreover, the equivalent circuit model of the proposed MM resonator is in good agreement with practical measurements, validating the simulation results. The new tuning method for MM resonators holds the promise for future sensing applications and wireless communications.