Compact High-Gain and Wide-Azimuth-Beam Filtenna for V2X Communication

This communication presents a high-gain filtenna with a wide azimuth beam and high out-of-band suppression for vehicle-to-everything (V2X) communications. The filtenna is composed of a shorting double-sided parallel strip line (DSPSL) with a metal via, a pair of dipole arms, U-shaped strips, and a board in a Shark-Fin housing. The DSPSL operates under half-modes for compact size. Two adjacent modes of the DSPSL are analyzed to generate a radiation null. The electric dipole is designed utilizing high-order modes to achieve high gain. Furthermore, a unidirectional radiation with high gain and wide beam is obtained by combining the electric dipole with the DSPSL. U-shaped strips are introduced into the filtenna, which can not only obtain the other radiation null but also increase gain and front-to-back ratio. Without extra filtering structures, a quasi-elliptic filtering response with out-of-band broadband suppression is realized. Characteristic mode analysis and equivalent circuit model are utilized for filtenna design. For demonstration, the proposed filtenna is implemented. The maximum gain in the azimuth plane is 7.6 dBi with the beamwidth of 124°. The out-of-band suppression is over 18.3 dB within 3–5.7 GHz. Featuring a compact size, high gain, wide azimuth beam, and harmonic suppression, the proposed filtenna is suitable for V2X communications.