Miniaturization of Split Ring Resonator and Spiral Resonator with Interdigitated Ring Edges for Small Sensor Applications

A novel technique for the further miniaturization of the Split ring resonator and the spiral resonator is proposed in this paper. With interdigitation, the resonance frequency of the conventional SRR and SR are brought down from 1.08 GHz to 0.84 GHz which is about 22% reduction and from 0.54 GHz to 0.41 GHz which is about 24% of their original resonance frequencies respectively. Interdigitating essentially increases the per unit length capacitance which plays a key role in reducing its resonance frequency. The technique is explained theoretically and proved experimentally by loading it on to a microstrip line as a Complementary SRR and Complementary SR. Applicability of this new technique for the further miniaturization of multiple turn forms of Split ring resonator and spiral resonator unit cells beyond their saturation limit is also discussed.