Metamaterial-Inspired Microwave Sensor for Enhanced Liquid Characterization

Liquid characterization is crucial in various fields, including biomedical and agricultural applications. This study introduces a novel microwave sensing setup that integrates an ultra-wideband antenna with a Two-layer, metamaterialinspired passive tag for precise liquid analysis. This design effectively detects small variations in the dielectric properties of materials, focusing on real-time water quality monitoring for precision agriculture. An aqueous solution of ammonium chloride (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{NH}_{4} \text{Cl}$</tex>) at concentrations ranging from 10 ppm to 6000 ppm was investigated using the proposed sensor. The sensor demonstrated an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{8. 1 5 ~ d B}$</tex> amplitude shift at its resonance frequency as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{NH}_{4} \text{Cl}$</tex> concentration varied from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{0}$</tex> to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{6 0 0 0}$</tex> ppm, highlighting its sensitivity and reliability. This innovative sensing system represents a significant advancement in liquid characterization technology, providing a real-time solution for monitoring changes in liquids. Its application in agricultural fertilizer management can help mitigate challenges associated with liquid characterization, ensuring improved efficiency and environmental sustainability.