Preparation Design and Implementation of a Portable Microwave Sensor for Characterization of Edible Oils

The design and implementation of a portable, low-cost microwave sensors for a wide range of sensing applications is presented in this letter. The proposed sensor utilizes a planar transmission line with a defected ground structure (DGS) comprise of three folded complementary split ring resonators (CSRRs). The use of CSRR-based DGS makes the design acts as a stop band filter with high quality factor at the resonant frequency of the resonator. The proposed sensor design is very compact in dimensions of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$0.214 \times 0.16{{\lambda }_0}.$</tex-math></inline-formula> A low loss Arlon material of dielectric constant 2.5 and loss tangent 0.002 is used as substrate of the sensor. The sensor gives a sharp stop band characteristic at the industrial, scientific and medical (ISM) bands with high Q value of 51.63 to characterize different oil samples. The portable sensor demonstrates highest sensitivity of 11.04% in characterization of edible oils, such as mustard oil, castor oil, olive oil, and flaxseed oil. The low-cost and compact design makes them ideal for real-time monitoring in industrial, agricultural, and healthcare applications particularly for food safety. Experimental results validate the effectiveness of the proposed sensors, showcasing their potential for widespread adoption in various sensing scenarios.