Angular and polarization study of flexible metamaterials with double split-ring resonators on parylene-C substrates

This paper presents a tunable and flexible metamaterial with double split-ring resonators arrays fabricated on parylene-C substrates. We numerically and experimentally designed four structures with different angles between the outer and inner split-ring resonators to achieve tunability of the multiband metamaterials and investigated the effect of polarization and incident angle direction of terahertz waves on the transmission spectra of metamaterials. The results show that the first resonant frequency increases slightly when the inner rings rotate, which realizes frequency modulation. The polarization study of the structure indicated that it might be applied as a dual-band amplitude modulation device. Finite-difference time-domain numerical simulations were further conducted to calculate the electromagnetic field as well as surface current distributions at the resonant frequencies. It demonstrated that the two resonant dips are caused by different mechanisms.