Metamaterials have a wide range of potential uses in areas such as optics, transmission lines, and RF design. The simplest metamaterial structures are Split-Ring Resonators (SRR) and Complementary Split-Ring Resonators (CSSR). Through the combination of various forms of these structures, different applications in the areas previously stated can be achieved. Under this investigation, a metamaterials transmission line was realized through micromachining a Liquid Crystal Polymer (LCP) substrate. Not only does LCP possess useful RF properties, it can also be easily micromachined. This transmission line consisted of several CSSRs in series, which performed as a high-order, high-frequency high-pass filter. This structure was unique to most metamaterial structures because LCP is a flexible substrate. It was observed that the resonant frequency of the filter did not change when the LCP transmission line was flexed in various ways. Next, micromachined vias were etched through the LCP substrate to demonstrate that these features do not affect the filter's response. Through utilization of these vias, the metamaterial structures can be physically conformed to nearly any shape or mounted onto another object without affecting the filter's response. As demonstrated in a simple filter structure, the shape manipulation has very little effect. Theoretically, extrapolating these methods to the development of metamaterials 3D RF invisibility cloaks, that are easily realizable and mountable onto an object, could prove useful.
A rigorous analysis of high-order electromagnetic invisibility cloaks
