Design and Performance Analysis of Slotted Vivaldi Antenna for Radar Systems

This paper presents a modified design of Vivaldi antenna for X-band applications by introducing rectangular slots to improve radiation efficiency. The surface current distribution of the general Vivaldi antenna is studied and rectangular slots are added with a circular resonating cavity to improve the antenna parameters. The slots and circular resonating cavity are optimized for dimensions and offsets using Ansys HFSS. The design is implemented on Rogers RT Duroid 5880<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">TM</sup> with a thickness 1.57 mm. The optimized structure is fabricated, and the experimental validation is carried out in an anechoic chamber. The modifications result in a gain of 7.94 dB, bandwidth of 970 MHz (12.03.%), and a return loss of 23.44 dB, outperforming the general Vivaldi antenna design. The measured results closely align with the simulated data, confirming the reliability of the proposed structure. These enhancements make the proposed design well suited for RADAR, satellite communications, and high-frequency data transmission systems.