Circular polarization V2X antenna design, production and measurement

In this study, a new dual-band microstrip antenna design, simulation and measurements have been conducted for the wireless communication standard enabling vehicles to communicate with each other, infrastructure, and other objects under the concept of Vehicle-to-Everything (V2X). This antenna covers the operating frequencies of 2.45 GHz used in WLAN applications and 5.9 GHz in the Dedicated Short Range Communications (DSRC) band. The proposed antenna, possessing circular polarization characteristics, was meticulously designed to achieve high gain and efficiency through detailed parametric studies and simulation processes utilizing the CST Studio Suite program. The design was completed in four stages, with S11 (reflection loss) curves simulated separately in each stage to demonstrate the operating frequencies and bandwidths. To examine the effect of the substrate thickness used in the proposed antenna on antenna performance, designs were carried out with five different thickness values, and the results were analyzed. It was observed that optimum performance was achieved when the thickness reached 1.6 mm. Additionally, four different substrate materials including FR4, Arlon AD250C, Rogers Ro3003, and Aluminum Nitride were evaluated for dielectric constant analysis, and among these materials, FR4 with an electrical permeability of 4.3 and a thickness of 1.6 mm exhibited the best antenna performance. Through optimization studies, gain values of 6.77 dBi at 2.45 GHz and 10.7 dBi at 5.9 GHz were obtained. Furthermore, axial ratio curves were obtained through simulation studies, confirming the circular polarization feature of the proposed antenna. Finally, to validate the simulation results of the computer-designed structure, the antenna was manufactured and gain and scattering parameter measurements were conducted in an RF/Microwave laboratory environment, revealing a significant parallelism between the measurement results and the simulation results.