Compact and Gain-Enhanced Vivaldi Antenna Design Using Nonuniform Slot Profile Optimization and Aperture Dielectric Loading

This letter introduces an efficient and compact design for ultrawideband applications, achieving both size reduction and enhanced gain. By using nonuniform slot lines as the radiation structure and adding extended ground branches, the design achieves significant miniaturization. The antenna circuit length is reduced from 27.2 mm to 14 mm, and the substrate from 41 mm × 48 mm to 32 mm × 25 mm, while maintaining a gain of 3.2 dBi to 7.4 dBi. In addition, a synergistic coupling board and a compact dielectric lens structure are loaded, which increases the gain to 4.1 dBi to 9.6 dBi and significantly enhances the radiation directivity. The experimental and simulation results show good consistency. This study realizes the miniaturization and maintains the gain, which verifies the effectiveness of the miniaturization design.