An artificially structured vivaldi antenna for broadband applications

Like other types of antennas, such as dipole, slot, and bowtie antennas, the Vivaldi antenna is widely used because of its advantages, including stable gain characteristics, narrow beamwidth, and wide bandwidth. Incorporating these unique characteristics into the antenna design aims to increase its effectiveness in meeting the desired specifications for broadband applications. This research addresses the challenge of developing a compact antenna design that achieves both high gain and wide bandwidth. To meet this challenge, the Vivaldi antenna (VA) was selected and examined in four stages to assess how structural modifications affect its performance parameters. This study proposes a novel Vivaldi antenna developed progressively from basic techniques to more sophisticated structural configurations. Antenna performance improvement is achieved by incorporating artificial periodic structures (APS) on the front, right, and left sides of the antenna, forming the VA+APS design. Adding the periodic structure successfully broadens the bandwidth and increases the gain without altering the antenna’s original shape. Furthermore, integrating an artificial lens (VA+ALS) enhances the antenna’s gain, reaching 9.1 dBi. The dimensional changes are minimal, ensuring the design remains compact. The final proposed antenna (VA+APS+ALS) measures 68.5×70 mm², offering a gain of 6.4 dBi and a bandwidth of 3.2 GHz with fractional bandwidth of 82.1%.