Bandwidth Enhancement of a 5.9 GHz V2X Patch Antenna Using a Single Edge-Notch Slot

Abstract

A compact rectangular microstrip patch antenna with enhanced impedance bandwidth is proposed for vehicular V2X applications operating at the 5.9 GHz ITS band. The design employs a single edge-notch slot to improve impedance matching and broaden the operational bandwidth. Full-wave electromagnetic simulations are performed using MATLAB Antenna Toolbox, enabling analysis of main antenna parameters including surface current distributions. Simulation results demonstrate that the slot excites an additional resonance that merges with the fundamental mode, increasing bandwidth from 240 MHz to approximately 500 MHz for VSWR < 2, fully covering the 5.85–5.925 GHz V2X band. Experimental measurements of VSWR show a bandwidth of approximately 490 MHz around the 5.9 GHz center frequency. Calculated peak gain (~8.3 dBi) and front-to-back ratio (~18.5 dB) are preserved. A parametric study of ground plane dimensions reveals the evolution of back-radiation patterns due to edge diffraction.