A Novel Windshield Antenna with Horizontal Forward Wide-Azimuth Coverage for V2X Communications

This paper presents a novel vehicular windshield antenna for V2X communications, demonstrating horizontal forward wide-azimuth coverage when inclined at 30°. The design introduces an innovative CPW-fed second-order monopole antenna (SOMA). By exciting equal-amplitude, out-of-phase currents on the radiating arm, it forms a two-element end-fire array, enabling bidirectional radiation on a laminated glass substrate (LGS). Furthermore, parasitic strips are symmetrically loaded beside SOMA to control current amplitude distribution on the radiating arm, resulting in a 5 dB enhancement of front-to-back ratio (FBR). To address TE₀ surface wave (SW) interference caused by the electrically large LGS, periodic cross-shaped electromagnetic bandgap (EBG) units and a metal ground are integrated around the SOMA, effectively restoring radiation performance. Simulations results show that stable radiation characteristics under electrically large LGS conditions: A forward maximum gain of 10 dBi at 5.92 GHz, ±45° 10dB-BW. This work overcomes limitations imposed by electrically large LGS, providing an innovative technical framework for windshield antenna in intelligent connected vehicles (ICVs).