Abstract

A magnetically tunable negative refractive index material is made by incorporating periodic metallic wire array (PMWA) into yttrium iron garnet (YIG) slices. Applied by external magnetic field, the effective permeability of YIG is negative in certain frequency band. PMWA also exhibit negative effective permittivity in certain frequency band. In the overlapping area of two bands, the effective permeability and effective permittivity are negative simultaneously. Consequently, negative refraction occurs in the composite. The negative refractive phenomenon is observed by prism experiment from 7.5 to 8.5 GHz under 2200Oe external magnetic field. The experimental results show that the composite medium consisting of PMWA with negative effective permittivity and YIG slices with negative effective permeability is negative refractive index material.

Key words: Periodic metallic wire array, yttrium iron garnet, magnetotunable, negative refractive index material.