Tunable High Frequency Permeability of Metamaterials

In this paper, an approach of tuning the magnetic permeability of split-ring resonator (SRR) has been presented. A varactor diode has been embedded into a SRR structure, and its capacity can be tuned by controlling the applied voltage. By this method, the resonance frequency and effective permeability are found to be easily tuned. Using the Finite-Difference-Time-Domain method and retrieval method, we have respectively simulated the tunablity of permeability by changing the geometry of split and by changing the applied voltage of varactor diodes. The HFSS simulation results shown that the resonance frequency of permeability shifts toward a higher value with increasing the size of split, while it is also found that the resonance frequency of permeability shifts toward a lower value by increasing the applied voltage.