A novel ultrawideband dipole antenna/array

This paper presents a novel ultrawideband magnetoelectric dipole antenna/array. The operational bandwidth is significantly enhanced through three key design strategies involoving adding cross shaped slots on the electric dipoles, loading metal posts on the ground plane, and introducing the horizontal metal plates on the metal posts, the operational bandwidth can be enhanced significantly. Additionally, an arch-shaped feeding probe is employed to improve isolation by optimizing the feed structure. To ensure stable gain performance, several triangle slots are etched on the ground. These techniques collectively enable the proposed antenna to realize a 110% fractional impedance bandwidth ranging from 1.09 GHz to 3.58 GHz, where S₁₁ is less than −10 dB. Furthermore, the antenna exhibits exceptional performance across the entire bandwidth, including an isolation level exceeding 32 dB and a stable gain ranging from 6.1 to 8.5 dBi. The antenna achieves a compact sizes of 0.78λ_center × 0.78λ_center × 0.25λ_center (where λ_center corresponds to the center frequency). To further enhance gain and enable beam scanning, an eight-element array based on this antenna design is simulated. The antenna array retains a 102% operational bandwidth for all ports. When all the antenna elements are excited with identical amplitude and phase, the gain achieves a gain of 14.0 to 19.8 dBi, with a peak gain occurs at 3 GHz. Beam scanning is successfully demonstrated across the entire operating band, achieving a scanning range of ±45° from 1.2 to 2 GHz and ±30° from 2 to 3.4 GHz.