Dual-band negative-permittivity metamaterial using crossed loop resonator

This paper presents a novel dual-band negative-permittivity metamaterial (MTM). The MTM is based on a crossed loop resonator (CLR) which exhibits negative-permittivity property at 4.85–5.58 GHz and 9.34–15.48 GHz frequency bands under the normal incidence of EM wave. The MTM shows epsilon-very-large (EVL) and mu-near-zero (MNZ) properties near the resonance frequencies (4.85 GHz and 9.34 GHz). Thus, low-impedance characteristics are obtained around the resonance frequencies of the CLR. The CLR MTM is insensitive to the polarization and incident angle of the imposed EM wave (for incident angle < 20°). This MTM, which is polarization and incident angle independent, can be used for gain enhancement of magnetic dipole antennas, design of filters and ultrathin microwave absorbers.