Compact Spoof Surface Plasmon Polaritons Waveguide Integrated With Blind Vias and Its Applications

A novel compact spoof surface plasmon polaritons (SPPs) waveguide integrated with blind vias is proposed in this brief. Depending on the groove orientation, the SPP structure leads to asymmetrical electromagnetic (EM) field confinements in the transverse plane, where the EM field is strongly confined around the groove orientation but much weaker in the opposite side. Due to this strong field confinement, the measured crosstalk between two SPP waveguides with 1 mm edge separation is -25 dB in 3-13 GHz band, a reduction of 18 dB on average when compared with microstrip line implementation. Due to the weaker field confinement, energy from the SPP waveguide can be easily coupled into other parasite structures for filter designs. By loading quarter-wavelength SPP resonators along the main SPP waveguide, we can introduce notched frequencies in the transmission. The number of notches and their frequencies can be controlled by SPP dispersion.