Capacitor-Loaded Coplanar Waveguide Spoof Surface Plasmon Polariton With Reduced Transversal Width

To reduce transversal width, a new spoof surface plasmon polariton (SSPP) based on coplanar waveguide (CPW) is proposed. By using capacitor loading technique to control the dispersion characteristics and electromagnetic field, the proposed capacitor-loaded CPW SSPP exhibit a similar transmission performance to conventional unloaded CPW SSPP TL, but with a transversal width reduction up to 64%. On this basis, another modified capacitor-loaded CPW SSPP is presented by changing the groove shape from strip-shape to T-shape. Results validate that the transversal width of the T-shape CPW SSPP is only 24% to that of conventional unloaded CPW SSPP. Besides, much more tighter field confinement is achieved for both the two proposed CPW SSPPs. Such results are of great significance to reduce the size of plasmon devices in microwave regime.