Endfire antennas based on spoof surface plasmon polaritons

A linear polarized (LP) endfire antenna based on spoof surface plasmon polaritons (SSPP) is proposed, which is composed of a feed monopole and ultrathin corrugated metallic strips. The metallic strips are utilized to couple guided wave into SSPP, propagate SSPP, and radiate the SSPP into free space. As an example, an X-band prototype is designed, fabricated, and measured. Both the simulated and measured results show good agreement, and verify that the proposed antenna behaves good performances. Similar to travelling wave antennas, gain of the proposed antenna is in proportional to the length of the strips structure. Furthermore, a circular polarized (CP) endfire antenna is also designed by arranging two LP antennas with different strip height in orthogonal. The simulated results verify our prediction.