Characterization of a variation on AFIT's tunable MEMS cantilever array metamaterial

Abstract

Metamaterials are devices with embedded structures that provide the device with unique properties. Several applications for metamaterials have been proposed including electromagnetic cloaks, lenses with improved resolution over traditional lenses, and improved antennas. This research addresses an obstacle to practical metamaterial development, namely the small bandwidth of current metamaterial devices. This research characterizes the effectiveness of several metamaterial designs. The basic design incorporates a microelectromechanical systems (MEMS) variable capacitor into a double negative (DNG) metamaterial structure. One set of devices is fabricated with the MEMS capacitor in the gap of the split ring resonator (SRR) of the DNG metamaterial. Applying voltage to the MEMS device changes the effective capacitance, thereby adjusting the resonant frequency of the device. Additionally, similar devices with three possible capacitor layouts are examined with stripline measurements and computer models. Recommendations for design improvements are provided. The initial capacitor layout with MEMS capacitors in the split ring gaps is recommended for future design iterations with adjusted gap capacitance values.