Design and Analysis of a Compact FR4-Based Vivaldi Tapered Slot Antenna for Ground-Penetrating Radar

This paper presents the design and simulation of a compact Vivaldi Tapered Slot Antenna (VTSA)fabricated on an FR4 substrate, specifically optimized for Ground-Penetrating Radar (GPR)applications. The antenna structure features a tapered slot profile to achieve effective end-fire radiation andimproved directivity. Simulated using Ansys HFSS, the antenna operates efficiently across 3.84 GHz, asdefined by the –10 dB return loss criterion. A minimum return loss of –26.9 dB was observed at 3.84 GHz,indicating excellent impedance matching. The radiation analysis revealed a maximum gain of 1.78 dBi, witha minimum gain of –24.47 dBi, demonstrating good directivity and effective suppression of side and backlobes. These characteristics, along with the antenna’s compact size and low-cost fabrication using standardPCB processes, make it a strong candidate for shallow-depth subsurface imaging in GPR systems. Theproposed design offers a cost-effective, high-performance solution for near-surface sensing applicationsrequiring focused energy delivery and minimal reflection loss.