A Dual-Band Epsilon-Negative Material Design Using Folded-Wire Structures.

A novel design of epsilon-negative (ENG) material which can exhibit negative permittivity at two nearby bands is presented in this paper. With the unit shape as an unsealed rectangle frame, the components of this ENG material are two folded wires with different dimensions. Each folded-wire structure can achieve electric resonance at a certain frequency band by appropriately adjusting its dimensions. Its electromagnetic properties are then retrieved to demonstrate that the dual-band electric resonances can be obtained in our sample. With the aid of numerical simulation, the transmission property of the proposed dual-band epsilon-negative material is further investigated. And the result shows that the stop band for each folded wire (permittivity ε < 0) is easily adjusted by changing the designing parameters, without influence on the other nearby resonance frequency. It provides an advancement of dual-band and low mutual coupling resonances design. It is also promising that our approach will be effective to make this kind of dual-band ENG material applied into the areas of reconfigurable antennas and their arrays. [ABSTRACT FROM AUTHOR]