Differential transmission lines with surface plasmon polaritons at low frequencies

A new kind of differential microstrip lines by introducing periodic subwavelength corrugation in the edge, which is able to support low‐frequency spoof surface plasmon polaritions, is proposed. The surface current distribution of the subwavelength periodic corrugated microstrip is numerically analysed. A kind of differential to single‐ended microstrip coupling circuit is designed to investigate the ability of suppressing the crosstalk of such a subwavelength periodic corrugated differential pair. Experimental results show that such a structure can be utilised to effectively suppress crosstalk, and to reduce the transformation between differential‐mode and common‐mode signals.