Design and Performance Analysis of Slotted Vivaldi Antennae in X-Band

The Vivaldi Antenna has gained significant popularity and importance in radar systems, due to its wide bandwidth, fairly high gain and radiation features. The modifications in the structure of Vivaldi Antenna performance within the X-band are discussed in this paper. The paper discusses two modified Vivaldi designs, their plotted characteristic features and observations made on them. The Conventional Coplanar Vivaldi Antenna has two peripheral slots added, which help reduce the back lobes and improve the return loss. The Modified Vivaldi Antenna includes the addition of a circular slot line cavity, multiple rectangular slots along its periphery, and an unconventional antenna base, with the width being longer than the length. The addition of the rectangular slots decreases the presence of back lobes, while simultaneously providing lower return loss, peaking at a minimum of 39.59dB. Additionally, a circular slot line cavity is shown to provide increased overall gain, with a peak of 7.91dB in this study.