A Compact Multiband Shark-Fin Antenna for Integrated V2X Communication Systems

A compact multiband shark-fin antenna is proposed for integrated vehicle-to-everything (V2X) platforms. The design incorporates five radiating elements within a compact 90×15×30mm3 footprint, simultaneously supporting FM (88–108 MHz), TETRA (380–470 MHz), wideband cellular (0.68–6.05 GHz), and dual-band Wi-Fi services. Wideband cellular operation is realized using two mirrored planar inverted-F antennas (PIFAs), while a dual-band IFA provides Wi-Fi connectivity for in-vehicle and vehicle-to-infrastructure communications. The FM and TETRA elements employ compact meandered-line configurations to satisfy stringent rooftop space constraints. To improve multi-radio coexistence, the FM radiator is strategically placed between the two cellular elements, achieving inter-element isolation better than −15 dB across all operating bands. Experimental results demonstrate stable radiation performance, with realized gains ranging from 1.5 dBi to above 5 dBi and cross-polarization levels below −13 dB, in good agreement with simulations. With overall dimensions of 90×15×30mm3, the proposed antenna is well suited for integrated V2X applications.