Multilevel dendritic structure with simultaneously negative permeability and permittivity

We study experimentally and numerically the transmission properties of the multilevel dendritic structures. This kind of structure produces one electric resonance and multiple magnetic resonances in different frequencies. In the case of dendritic structure alone, we can tune the magnetic resonance peak into the negative permittivity regime by changing the dimension of dendritic geometry, and achieve a left-handed transmission band. Three-order dendritic structures are fabricated on one side of the dielectric substrate using the lithographic circuit board technique, and the left-handed behavior is observed experimentally between 8 and 12 GHz. It is found that the phase of S-21 of three-order dendritic structure has a sudden variation at the left-handed pass band. At the same time, the effective permittivity and permeability are simultaneously negative. (c) 2007 American Institute of Physics.