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A simple, compact, contactless, and high sensitivity metamaterial-inspired sensor has been developed to detect and classify precious transition metals in the S- and C-band regime, using reflection coefficients. A multi-band metamaterial, quadruple concentric circular split ring resonator, is specifically designed as a sensing enhancer, where the additional bands can effectively trigger the electromagnetic properties, as well as enhance the differentiation between the testing metal samples. The proposed sensor was tested on precious transition metals, silver, platinum, and gold thin slabs of various thicknesses, from 0.5 µm to 3 mm. Five resonances were established in the frequency range of 2–8 GHz. Distinguishable frequency responses generated from different metal samples at those five resonances specify the capability of classifying the metal contents and thicknesses.


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Progress In Electromagnetics Research B





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