Redshifting extraordinary transmission by simple inductance addition

By interpreting the extraordinary transmission phenomenon on the basis of induced surface currents, the potential of engineering Rayleigh-Wood anomalies is shown, or more specifically, moving down the resonant peak away from the Rayleigh-Wood's anomaly. The strategy presented here relies simply on enlarging the path explored by the induced-surface current so as to increase the inductance of the structure, shifting consequently the resonant peak to lower frequencies because of the 1/L1/2 dependence. This brings about two important consequences: The aperture is more subwavelength, which opens novel possibilities for realistic metamaterials, and the phenomenon emerges away from the onset of higher-order modes. Numerical as well as experimental results are given at the millimeter-wave regime supporting the initial assumptions.