Study on the Rotated SSPPs Structure and Its Applications in Antenna

A novel periodically rotated spoof surface plasmon polaritons (R-SSPPs) structure of s-shaped arms distributed along z-axis is proposed. The R-SSPPs structure can generate an endfire radiation lobe with rotating E-field in odd mode, and omnidirectional radiation pattern with higher gain in quasi-even mode under different polarization plane waves, respectively. The endfire antenna based on the R-SSPPs structure fed by a vertical monopole was designed and fabricated. It works in odd mode and achieves 20.35% impendence bandwidth from 2.185 to 2.68 GHz. It provides a circularly-polarized endfire radiation pattern with gain 6-7.43 dBi in the range of 2.41-2.52 GHz in experiment. Based on the same R-SSPPs structure, a broadside antenna fed by SMA connector through coplanar waveguide (CPW) connecting to the R-SSPPs axis was designed and fabricated. It works in quasi-even mode and provides a quasi-omnidirectional radiation pattern. Its available impedance bandwidth is about 24.3% ranging from 2.35 to 3 GHz with gain of 2-6 dBi. By using different feeding means, the proposed R-SSPPs structure can radiate different patterns with different polarizations, which can be quite promising for different applications coping with the dynamic environment.