Based on the mechanism of spoof surface plasmon polaritions (spoof SPPs), we present a kind of microwave band pass ¯lter in both theory and experiment, which is realized by periodic subwavelength metallic Domino array. The transmission bandwidth of spoof Based on the mechanism of spoof surface plasmon polaritions (spoof SPPs), we present a kind of microwave band pass ¯lter in both theory and experiment, which is realized by periodic subwavelength metallic Domino array. The transmission bandwidth of spoof