The Research Of Active Metamaterials And Metasurfaces

The advantage of metamaterials is that its electromagnetic parameters can be tailored. The metamaterial provides a powerful tool to control the properties of electromagnetic (EM) waves. With the development of metamaterials, more and more attentions are focused onthis area. This paper introduces the design of active metamaterilas and metasurfaces,and the main contributions are listed below:1. The design of a kind of switchable zero-index metamaterials (ZIMs) are introduced. The switchable zero-index metamaterial is implemented by split-ring resonators (SRRs) loaded with PIN diodes. When the PIN diode is switched off, ZIMs can be achieved. When it is switched on, the impedence of designed metamaterials matched that of free space, leading to the total transmission as expected.2. Anisotropic metasurface is designed. When the metasurface is wrapped on a moderate-sized PEC cylinder, various electromagnetic responses are exhibited according to the polarization of the incident waves. When illuminated by TE-polarized, the metasurface can act as an illusion coating; However, for TM polarized wave the metasurface acts as a mantle cloak.