Design of a Planar Sensor Based on Split-Ring Resonators for Non-Invasive Permittivity Measurement Articles uri icon


  • Virdee, Bal S.
  • Elwi, Taha A.
  • Lubangakene, Innocent D.
  • Jayanthi, Renu K.R.
  • Al Behadili, Amer Abbood
  • Hassain, Zaid A.Abdul
  • Ali, Syed Mansoor
  • Pau, Giovanni
  • Livreri, Patrizia
  • A├»ssa, Sonia

publication date

  • June 2023


  • 11


  • 23

International Standard Serial Number (ISSN)

  • 1424-3210

Electronic International Standard Serial Number (EISSN)

  • 1424-8220


  • The 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.


  • Mechanical Engineering


  • complex permittivity; microstrip technology; sensor; split-ring resonator