Multiband Frequency-Selective Surface With Five Resonance Peaks in Terahertz Band

We discuss a multiband frequency-selective surface (FSS) device with an irregular electromagnetic structure that has five resonance peaks in the terahertz (THz) regime. The compact asymmetric structure utilizes all components efficiently. Different modes, including LC and quasi-quadrupole resonances, are induced in each unit cell. Simulations indicate that each of the five resonance peaks has independent characteristics with different electric field and surface current distributions. The multiband FSS provides an alternative way to design THz multiband filters, modulators, absorbers, and sensors at small planar dimensions.