Three-level dendritic structure with simultaneously negative permeability and permittivity under normal incidence of electromagnetic wave

We present the model of three-level dendritic structure for left-handed metamaterials under normal incidence of electromagnetic radiation and investigate the electromagnetic responses in microwave band by simulation. The influence of branch lengths a, b, and c on the electric and magnetic resonance frequencies is studied by the transmission spectrum of single three-level dendritic structure. Moreover, the transmission of multiple three-level dendritic structures exhibits the interaction between the elements. To confirm the left-handed behaviors of three-level dendritic structures, the permittivity ε and permeability μ are calculated by S -parameter retrieval method. The results show that the ε and μ are indeed simultaneously negative around 9.2 GHz.