Free Space Measured Loss Comparison of Single and Double Ring Resonators for Negative Index Media
Abstract
Since the first demonstration of negative refractive index using nested or edge coupled split ring resonators and posts, various proposals have been made for improvement of the structures. Loss is an ongoing concern for these media at microwave frequencies and above. One alternate design uses broadside coupled split rings printed front to back on a substrate. This approach, which avoids bianisotropic effects of edge coupled rings, has been demonstrated successfully inside waveguide below cutoff. Our work here investigates the combination of similar broadside coupled rings (BCRs) with negative permittivity posts in a metamaterial prism, rather than the previous guided-wave medium. Free space measurement of negative refraction through a prism has become our standard for proof of negative index. Unlike rectangular wave guide, free space measurement also allows true transverse electromagnetic illumination. To observe the different effects of magnetic and electric coupling in the rings, two different orientations of the ring gap were used. One type has the gap aligned with the post and is symmetric about the electric field axis. The other has the gap turned 90 degrees from the post. The broadside coupled version of each orientation is measured and compared to a single ring version of the same dimensions and orientation for a total of four prisms.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 14, 2007
- Accession Number
- ADA472294
Entities
People
- Alvin J. Drehman
- Beverly W. Turchinetz
- Everett E. Crisman
- James W. Dean
- John S. Derov
Organizations
- Air Force Research Laboratory