Miniaturization of U-shaped multi-band metamaterial structures

In this study, transmission characteristics of single-sided and double-sided (in broadside-coupled configuration) U-shaped multiple ring resonators (UMRR) are investigated on a comparative basis for the purpose of miniaturization. Transmission spectra (i.e. |S₂₁| versus frequency curves) of both single and double sided UMRR topologies are computed by CST Microwave Studio for the special cases of unit cells with single ring and double concentric rings. Although all these unit cells have exactly the same physical size, simulation results have revealed that broadside-coupled UMRR topologies provide much smaller resonance frequencies (hence considerably smaller electrical sizes) as compared to their single-sided counterparts.