Low-loss and flexible terahertz bandpass frequency selective surface based on cyclic olefin copolymer substrate via solvent-free synthesis

Abstract

This study investigates a low-loss and flexible terahertz frequency selective surface (FSS) based on cyclic olefin copolymer (COC) film substrate, which is fabricated via a simple temperature-control method without the use of solvent. The measured frequency response of the proof-of-concept COC-based THz bandpass FSS matches well with the numerical results. Due to the ultra-low COC dielectric dissipation factor (order of 0.0001) in the THz band, the measured passband insertion loss at 559 GHz reaches 1.22 dB, which is much better than that of previously reported THz bandpass filters. This work indicates that the remarkable characteristics (small dielectric constant, low frequency dispersion, low dissipation factor, good flexibility, etc.) of the proposed COC material make it a great application prospect in the THz field.