Abstract
A numerical and experimental study of a tunable single-layered tunable fishnet metamaterials (TFMM) infiltrated with polymer dispersed liquid crystal (PDLC) in THz range is reported. The retrieving procedure of refractive index takes antiresonance phenomenon into account and is verified by the assumption in effective medium theory. An encapsulating technique that covers PDLC with a 1.5μm polyimide layer (skin layer) was applied to prevent volatile liquid crystal from escaping the PDLC and enable the deposition of metal layer while minimizing the Fabry-Perot effect of the skin layer on the TFMM measurements. Concept of tuning TFMM infiltrated with PDLC (PDLC-TFMM) was proven by measuring the frequency shift in the reflection coefficient (0.01THz), with an observed minimum negative refractive index of -15 at 0.55THz.