Design and Simulation of a UWB Vivaldi Antenna and Its Array Configuration for S, C, and X Band Applications

This paper presents the design and simulation of an ultra-wideband (UWB) Vivaldi antenna and its array configurations, targeting a broad frequency range from 1 GHz to 12 GHz, covering the $S, C, X$ bands. The proposed antenna is optimized for applications such as through-wall radar, groundpenetrating radar (GPR), and biomedical microwave imaging. A single-element Vivaldi antenna with dimensions of $75 \text{mm} \times 45 \text{mm}$ was initially designed, followed by the development of $1 \times 2,1 \times 3$, and $1 \times 4$ linear arrays to enhance gain and directivity. All models were simulated using CST Studio Suite. The results demonstrate low return loss ($\mathrm{S} 11<-10 \text{dB}$), VSWR $<2$, and directional radiation patterns with gain exceeding 3 dBi, confirming the suitability of the proposed design for high-resolution sensing applications.