Ferrite-based magnetically tunable left-handed metamaterial composed of SRRs and wires

We experimentally demonstrate a magnetically tunable left-handed metamaterial by introducing yttrium iron garnet rods into SRRs/wires array. It shows that the left-handed passband of the metamaterial can be continuously and reversibly adjusted by external dc applied magnetic fields. Retrieved effective parameters based on simulated scattering parameters show that tunable effective refraction index can be conveniently realized in a broad frequency range by changing the applied magnetic field. Different from those tuned by controlling the capacitance of equivalent LC circuit of SRR, this metamaterial is based on a mechanism of magnetically tuning the inductance via the active ambient effective permeability.