Alibakhshikenari, MohammadVirdee, Bal S.Elwi, Taha A.Lubangakene, Innocent D.Jayanthi, Renu K. R.Al-Behadili, Amer AbboodAbdul Hassain, Zaid A.Mansoor Ali, SyedPau, GiovanniLivreri, PatriziaAissa, Sonia2023-12-212023-12-212023-06-01Sensors 2023, 23(11), 5306; https://doi.org/10.3390/s231153061424-3210https://hdl.handle.net/10016/39149The permittivity of a material is an important parameter to characterize the degree of polarization of a material and identify components and impurities. This paper presents a non-invasive measurement technique to characterize materials in terms of their permittivity based on a modified metamaterial unit-cell sensor. The sensor consists of a complementary split-ring resonator (C-SRR), but its fringe electric field is contained with a conductive shield to intensify the normal component of the electric field. It is shown that by tightly electromagnetically coupling opposite sides of the unit-cell sensor to the input/output microstrip feedlines, two distinct resonant modes are excited. Perturbation of the fundamental mode is exploited here for determining the permittivity of materials. The sensitivity of the modified metamaterial unit-cell sensor is enhanced four-fold by using it to construct a tri-composite split-ring resonator (TC-SRR). The measured results confirm that the proposed technique provides an accurate and inexpensive solution to determine the permittivity of materials.15eng© 2023 by the authorsAtribución-NoComercial-SinDerivadas 3.0 EspañaSensorMicrostrip technologySplit-ring resonatorresearch articleMaterialeshttps://doi.org/10.3390/s23115306open access11Sensors23AR/0000033583