Abstract
Design and fabrication of a tunable fishnet metamaterial for potential THz beam steering device is presented. Split ring resonators have been the most popular unit-cell geometry for THz metamaterials. However, we have adopted the fishnet geometry for the application and utilizing polymer disperse liquid crystal (PDLC) as the tunable substrate. One of the advantages of using PDLC over conventional liquid crystal is the elimination of a cell to confine and encapsulate the liquid crystals. The trade-off of PDLC versus conventional liquid crystal performance is that a higher voltage is required to turn the PDLC on (approximately 2-10V/micron) as opposed to the conventional liquid crystal (1-5V/micron). In this report, we will present our latest development in the PDLC and its application in a tunable gradient fishnet metamaterial (TGFMM) array. The objective is to achieve a high Q and broader tunability of resonant frequency while maintaining a low operating voltage. We will present the latest simulation and experiment results of a polarization independent rotated square fishnet metamaterial design.