Multi-band Terahertz Transmission Using Frequency-selective Surfaces Based on 'F' Shapes Arranged in Odd-symmetry

Frequency selective surfaces employing band-pass transmission have potential applications in THz-filtering, imaging, remote sensing, and spectroscopy. In this paper, we propose a tri-band terahertz filter based on two element conductor array of F-shapes arranged in odd symmetry. In contrast to previous designs, the proposed structure is simple to fabricate because it involves just a few variables and is singly layered. Moreover; the proposed structure has transmission values of 0.94, 0.98 and 0.97 for first, second and third transmission bands respectively which is the best achieved so far with single layered structure. Simulation results show that three pass bands 0.777-0.898 THz, 0.936-1.024 THz, and 1.074-1.178 THz exist, having transmission values of 0.94, 0.98 and 0.97 at their center frequencies respectively. Surface current distributions reveal multi-resonance filtering characteristics. Moreover; the idea of multi-band transmission is supported by equivalent electric circuit model. This simple and single layered structure has potential applications in multiband terahertz devices.