A Simulation Study on Non-Invasive Glucose Sensor Based on Four-Concentric Ring Resonator

Abstract

This paper presents a compact four-centre complementary split ring resonator (FC-CSRR) designed for biomedical applications. The proposed sensor features an alumina ceramic dielectric resonator coupled with a $50 \Omega$ microstrip line. Glucose concentration is determined by placing the sample on the designated sensing area, where the permittivity of the aqueous solution varies with glucose levels. simulated results obtained using the CST Microwave Studio full-wave electromagnetic simulator. Additionally, a model of a blood layer is modelled by the Debye model. The evaluation of variations in the aqueous solutions reveals that the resonance frequency of the proposed sensor is approximately 5.2 GHz, with a sensitivity of $\mathbf{9. 6} \times \mathbf{1 0}^{-\mathbf{3}}$ $\mathrm{dB} /(\mathrm{mg} / \mathrm{dL})$ at 3.129 GHz. With dimensions of $65 \times 20 \times 1.34$ $\mathrm{mm}^{3}$. This design demonstrates significant potential for noninvasive monitoring of glucose levels across the clinical diabetic range, effectively distinguishing between hypoglycemic ($40 \mathrm{mg} / \mathrm{dL}$) and hyperglycemic ($500 \mathrm{mg} / \mathrm{dL}$) conditions.