Horizontally Polarised Crescent Electric Dipoles Enabled by Conformal Loop Balancing Device

ABSTRACT This work proposes a characteristic‐curve‐based design approach to wideband horizontally polarised (HP) electric dipoles. The orthogonality of limaçons and parabolas is deduced to reveal the mapping relationship between circular sector and crescent. In this way, analytical theory of sectorial antennas can be extended to cover the more generalised crescent antennas, which yields a co‐design approach to crescent electric dipole with balancing device conformal to its orthogonal characteristic curve. Unlike traditional linear dipoles, the crescent electric dipoles feature pure horizontal polarisation in both E‐ and H‐plane as well as wide bandwidth enabled by the shape of themselves and the conformal loop balancing devices: By varying the shapes of crescent dipole and loop balancing device according to the orthogonality of characteristic curves, the dipoles' bandwidth can be adjusted from 47.7% to 59.3% as desired. This suggests that the shape of balancing device should serve as a new degree of freedom in two‐dimensional (2‐D) electric dipole designs. Benefiting from its generality, robustness and simplicity, the proposed approach is cost‐effective and promising for advanced, wideband HP antenna designs and future complex‐shaped antenna designs.