Dual-Square-Split-Ring-Enclosed Microstrip-Based Sensor for Noninvasive Label-Free Detection

In this article, we present the use of a metamaterial-incorporated microwave-based sensor with a single port network for material characterization. The proposed sensor consists of a microstrip patch layer enclosed with a dual-square-shaped metamaterial split-ring. This structure has the dimensions of 20 x 20 x 1.524 mm(3) and a copper metallic layer is placed on a Rogers RT 6002 with a partial back layer as a ground. Two resonant frequencies are exhibited for applied electromagnetic interaction using a transmission line. The dual split rings increase the compactness and accumulation of the electromagnetic field on the surface of the conducting layer to improve the sensitivity of the sensor. The numerical studies are carried out using a CST high-frequency microwave simulator. The validation of the proposed sensor is performed with an equivalent circuit model in ADS and numerical high-frequency simulator HFSS. The material under test placed on the proposed sensor shows good agreement with the frequency deviation for different permittivity variations. Different substrates are analyzed as a host medium of the sensor for parametric analysis.