Wide-Angle Ultrawideband Tightly Coupled Array With Asymmetric Dipole Arms and Feeding Lines

This letter presents a dual-polarized tightly coupled dipole array based on an asymmetric architecture. Through co-design of asymmetric feeding and radiating structures, the wide-angle scanning bandwidth and port isolation of the array are effectively enhanced. Specifically, unequal-length dipole arms are adopted to suppress resonance modes that limit isolation. A balun composed of feeding lines with different diameters ensures stable impedance matching under wide-angle scanning. The array achieves a 4.5:1 bandwidth from 4 GHz to 18 GHz, supporting ± 60° scanning in both E- and H-planes with an active voltage standing wave ratio below 3. The port isolation remains better than 20 dB across the operating band, while the array height is only 0.09λ at 4 GHz. A 10 × 10 array prototype was fabricated and measured, showing good agreement with simulated results. This validates the integrated advantages of the design in achieving ultrawide bandwidth, wide-angle scanning, and high isolation, making it well-suited for modern wireless communication systems.