Microwave Sensors Based on Coplanar Waveguide Loaded with Split Ring Resonators: A Review
This article reviews the application of physical, chemical and biological sensing of materials via microwave sensors based on a coplanar waveguide (CPW) loaded with a split ring resonator (SRR). Many CPWs loaded with SRR structures from the literature are reviewed in this article. CPWs loaded with many shapes of resonators have been proposed, such as circular, square and rectangular-shaped SRRs and CSRRs based on a paired and an array, folded stepped impedance (SIR), square and circular electric – LC (ELC) SRRs, circular, square, rectangular and golden ratio spiral S-shaped SRRs, diamond-shaped tapered SRRs, horn-shaped SRRs and others. The working principle for each device is briefly described and compared. The strength of this article is to introduce the application of microwave sensors based on CPWs loaded with SRRs for measurement and characterization of physical, chemical and biological materials through electromagnetic interaction.