New star-fractal antenna devised as wireless sensor of the permittivity characterization measurement of Na2SO3 solutions

This study presents a wireless electromagnetic sensing system based on the resonant properties of the star-fractal antenna. Thus, it has been used for measuring the complex electrical permittivity of sodium sulfite solutions, according to both transmission and reflection efficiencies of the incident electromagnetic wave. The proposed antenna has been designed and simulated using the HFSS-Software (Ansoft High-Frequency Structure Simulator). The optimum resonant dimensions of the designed star-fractal antenna are (24.5 × 23 × 1.64) mm with a dielectric substrate (ε = 2.2). The proposed antenna operates on a single band applications, at frequency 2.4 GHz. Based on this antenna, several parameters have been calculated, such as the return loss, input impedance, and radiation patterns. Therefore, in this study, the designed antenna was used to fabricate a sensor to measure the electrical properties of liquids that depend on its concentrations. Thus, the various high concentrations of Na₂SO₃ solution (1–5) mol/L, were sensitized. Which were compared with the theoretical results using a special mathematical model to calculate the electrical properties of each concentration. Consequently, the good qualitative agreement results were measured for the real and imaginary parts of the complex permittivity at 99% and 92%, respectively.