利用铁氧体的外场调制特性,提出采用铁氧体作为金属环线结构的介质基板,实现频率可调左手材料.首先采用时域差分有限元方法数值模拟了基板材料参数变化的条件下,开口谐振环的频率可调性规律.随基板材料的介电常数或磁导率升高,与开口谐振环负磁导率对应的透射谷频率将显著降低.实验制备了一系列超高频软磁六角铁氧体,利用外加磁场有效调制了其磁导率.并通过实验表明,通过调控外加磁场可以有效地调控开口谐振环负磁导率对应的透射谷频率.
The left-handed material, whose permittivity and permeability are simultaneously negative, has some exotic electromagnetic properties, and is one of the most absorbing subjects in recent physical academic domain. This paper suggests that a tunable left- handed metamaterial can be realized by using ferrite as the substrate of metallic wire structure, owing to the field dependence of ferrite' s permeability. Finite element method was used to simulate the effect of substrate properties on the effective properties of a metamaterial slab. With the rise of substrate permittivity or permeability, the resonance frequency drops significantly. Ferroxplana has been prepared, and the field dependence of its permeability was studied.