Spoof surface plasmon-based bandpass filter with extremely wide upper stopband

Liu Xiaoyong^{1, 2}, Zhu Lei^{2, †,}, Feng Yijun^{1, ‡,}

(a) Dispersion relation of spoof SPPs for different groove depths h. The parameters d, a, and w are set as 7.0 mm, 6.0 mm, and 0.3 mm, respectively. (b) The corresponding transmission spectra.