Spoof Surface Plasmon Polaritons Developed from SIW Using Ring Slots and Vias

A new type of spoof surface plasmon polaritons (SSPPs) developed from conventional substrate integrated waveguide (SIW) using ring slots and vias is proposed in this paper. The asymptotic frequency lower cutoff the SSPP structure can be easily tuned by changing width SIW walls radius slot, respectively. trapezoidal microstrip line a small slot are used for efficient mode conversion to smoothly transit structure. presented SSPPs have flat bandpass filtering response with adjustable center bandwidth. In order better verify transmission characteristics, two filters relative bandwidths 61.7% 76.4%, respectively, fabricated measured. Good agreement between simulations measurements verifies design idea.