Sub wavelength plasmonic nano-antenna with modified ring structure for multi resonance application and circular polarization

In this article, two different novel models of sub-wavelength plasmonic nano-antenna with modified ring structures for multi resonance applications with circular polarization are presented. At first a quad-ring metamaterial structure is presented, in the following we modified the structure with gaps in each rings. Therefore, the second structure has more absorption and reflection cross section than the first model. The absorption cross section has increased from 1.2E+5 for the first structure at 300 THz to 4.2E+5 for the second structure at 175 THz. In addition, the reflection cross section has increased from 3.7E+5 for the first structure at 300 THz to 5.2E+5 for the second structure at 175 THz. On the other hand, the Enhancement of E 2 is an important parameter and shows antenna quality, which improved strongly since 120 (V/m) 2 to more than 13,000 (V/m) 2 at X-directions. Here, E-field distribution shows that the field is concentrated at gaps in both structures.