Axial Mode Planar Meander-Line Antenna With High-Gain Endfire Radiation Pattern Mounted on Large-Scale Ground Plane

This article presents a novel planar linearly polarized all-metal meander-line endfire antenna mounted on a large-scale ground plane. First, the proposed antenna utilizes a single-conductor meander line as its radiation structure, which operates in the axial mode to generate an endfire radiation pattern. The radiation structure involves radiation components perpendicular to the endfire direction and transmission components parallel to the endfire direction. Second, the phase constant properties of the proposed meander-line antenna are unique. On the one hand, the phase constant is merely tuned by the length of radiation components. The phase constant increases with the increasing length. On the other hand, the change rate of phase constant versus frequency is only determined by the length of transmission components. The change rate decreases with the increasing length. The independent controllability of the phase constant can facilitate the design and analysis; thus, the Hanson-Woodyard (H-W) condition can be satisfied easily to achieve a high gain. Moreover, the proposed meander-line antenna can gain energy from dual paths including the space and the conductor, achieving uniform aperture distribution and a high gain-to-length ratio. Finally, to verify the proposed design concept, an eight-element planar meander-line endfire antenna is designed and fabricated. The measured maximum gain is 12.0 dBi, resulting in a high gain-to-length ratio of 7.3. Also, the meander-line topology provides a potential solution for compact dual-polarized antennas. The proposed novel linearly polarized meander-line antenna can be a promising candidate for wireless communication in transportation systems.