COMPREHENSIVE REVIEW OF SINGLE- AND DOUBLE-SPLIT RING RESONATORS: ANALYTICAL MODELLING, ELECTROMAGNETIC RESPONSE, AND MODERN APPLICATIONS

Abstract

Split-ring resonators (SRRs) are fundamental meta-atoms in metamaterial research because they enable tailored electromagnetic responses through geometrical design. This review examines the physical principles, analytical modelling, and modern applications of SRRs, with emphasis on the distinction between single split-ring resonators (SSRs) and double split-ring resonators (DSRRs). The discussion synthesizes prior studies on artificial magnetism, subwavelength LC resonance, and the roles of symmetry and bianisotropy, and it further outlines an analytical framework that incorporates magnetic inductance, electron kinetic inductance, gap capacitance, and surface capacitance for improved resonance-frequency prediction, especially at high frequencies. The review also summarizes the electromagnetic behaviour of SRRs at resonance through the distributions of electric field, magnetic field, surface current, and induced dipole moments. In addition, recent applications in microwave filters, antennas, and sensors are discussed to show how these resonant properties are translated into practical device functions. Overall, the review highlights that a rigorous understanding of SRR geometry, equivalent-circuit parameters, and symmetry-dependent coupling is essential for the accurate analysis and effective design of next-generation microwave and optical metamaterial devices.