Abstract
This article presents a compact, cost-effective, and contactless fractal modified electromagnetic bandgap structure (EBG)-based microwave sensing platform for dielectric characterization of liquids by analyzing the variation in the reflection coefficient of an antenna. The reported design is composed of a triangular-shaped antenna ( 0.323\lambda _{\mathrm {o}}\times 0.323\lambda _{\mathrm {o}} ) placed over a 3 \times 3 array of Cesaro fractal-based EBG plane ( 0.67\lambda _{\mathrm {o}} \times 0.67\lambda _{\mathrm {o}} ) operating at 2.45 GHz. A significant enhancement of the {E} -field in the sensing region has been achieved with the incorporation of Cesaro fractals in the EBG plane which results in increased sensitivity and compactness. To validate its performance, absolute solutions of butan-1-ol, methanol, and water are loaded, and a maximum measured sensitivity of 0.875% and a maximum quality factor of 90.05 are achieved. Moreover, a maximum rms error in retrieved values of dielectric constant and loss tangent of liquid under test is found to be 1.092% and 0.813%, respectively. Our demonstrated EBG-based sensor has a compact footprint with good precision, affordability, and ease of operation in detecting liquids for microwave sensing applications.