m-Shaped SSPPs Structure to Low Profile Vertically Polarized Antenna With High Gain to Be Conformal With Vehicle Shell

An m-shapedspoof surface plasmon polaritons (SSPPs) structure as well as its application into end fire antenna with vertical polarization, low profile and compact size are proposed to be conformal with vehicle shell. Beside the primary odd SSPPs mode in the center, extra even mode at the top horizontal arms and odd mode at the end of the arms are introduced through folded arms. Consequently, the end-fire pattern can be adjusted by varying the aperture size. The multiple modes of SSPPs structure enable the antenna to operate in dual bands. The 1
^st
mode operates from 447 to 515 MHz while the 2
^nd
mode works from 0.97 GHz to 1.81 GHz simultaneously in simulation. The profile of the manufactured prototype antenna is merely 0.1
${{\rm{\lambda }}_0}$
(@ 487 MHz). It achieves a measured gain peak of 8.4 dBi with HPBW 111.9
$^\circ $
in the 1
^st
mode around 500 MHz and gain peak of 9.2 dBi at 1.6 GHz in the 2
^nd
mode. It can be a very promising candidate for conformal antenna being embedded into the thin shell to high load bearing application on the high-speed vehicles for mobile communication.