Modeling and Applications of RF and Optical Negative Index of Refraction Materials, 14-R8050Printer Friendly Version
Inclusive Dates: 04/01/09 Current
Background - The focus of this project is to develop modeling capabilities of negative index of refraction materials and apply the modeling skills in the construction of two specific applications: an antenna and a filter.
Approach - Several common types of negative index material inclusions were modeled: split rings, Sievenpiper ("mushroom") structures, rod arrays, hole arrays and fishnet structures. The models from at least two of the inclusion types will be used to design an electromagnetic band gap material for use as an engineered ground plane under a dipole antenna, and in a band pass filter printed on flexible substrates.
Accomplishments - Thus far, the project team has created negative index material models and conducted parametric sweeps useful in material design. The team fabricated and tested dipole antennas that use an engineered ground plane composed of a Sievenpiper structure. The Sievenpiper structure possesses an electromagnetic band gap, preventing energy-sapping surface waves from propagating. Additionally, the Sievenpiper structure controls the reflection impedance of the ground plane. These two properties allow an antenna directly in contact with the surface to radiate well. This behavior was demonstrated in the laboratory. This project is ongoing, and the filter application work is under way.