Rotationally symmetric resonator-based metamaterial for wideband EMI shielding and blood dielectric property sensing applications

Abstract

This paper presents a rotationally symmetric metamaterial (MTM) designed for electromagnetic interference (EMI) shielding and blood dielectric sensing applications. The geometry of the MTM unit cell ($9.6\mathrm{mm}\times$ $9.6\mathrm{mm}\times 1.6\mathrm{mm}$) is optimized through CST simulation. The array of unit cells ensures the S₂₁ resonance at 5.961 GHz, with a broader bandwidth of 4.28 GHz (71.80 %) spanning from 3.75 to 8.03 GHz for the optimized dimensions of various segments of the rotationally symmetric unit cell. Utilizing field distribution, surface current, and effective parameter responses, the resonance phenomena are analyzed. The array structure of the MTM achieves a peak shielding effectiveness of 39.78 dB within the C-band while maintaining angular stability. Additionally, it performs nonlinear sensing responses, establishing a high-frequency deviation ranging from 4.037 to 4.230 GHz and demonstrating a high sensitivity of 4.44 %, which enables it to detect variations in blood dielectric properties. For sensing analysis, samples are replicated in a laboratory to accurately imitate blood dielectric properties. The performance of the designed MTM is validated by prototype measurements, which align well with the simulations. The findings confirm the design's effectiveness for EMI shielding in microwave communication and its potential for blood dielectric sensing in biomedical applications.