Wireless Experimental Determination of Dispersion Curves of Spoof Surface Plasmon Polariton Modes Supported by a Transmission Line

Excitation of spoof surface plasmon polaritons (SSPPs) by means of a dipole antenna is considered to experimentally assess the dispersion curves of the two first modes guided by a meandered transmission line (TL). First, simulated dispersion curves bring out even and odd symmetries of the SSPP modes highlighted by magnetic field mappings. Then, a dipole antenna with vertical and horizontal polarization is proposed for generating the even and odd propagation modes by near‐field magnetic coupling, respectively. Experimental validation is carried out with a SSPP TL fabricated on a flexible substrate (Kapton). For each mode, experiments show a pass‐band feature of the transmission between two antennas coupled to the SSPP TL with ripples related to the presence of a standing wave. Finally, the dispersion curves are experimentally achieved using a de‐embedding method applied on the scattering parameters directly measured between antennas without the need of a mode conversion structure. Experimental results are favorably compared with the simulated transmission and dispersion curves. Excitation of spoof surface plasmon polaritons (SSPPs) by means of a dipole antenna is considered to experimentally assess the dispersion curve of the odd and even modes guided by a meandered transmission line (TL) fabricated on a flexible substrate (Kapton). Experimental results are favorably compared with the simulated transmission and dispersion curves.