A Terahertz Narrowband Metamaterial Absorber for Terahertz Sensing Applications

Metamaterial absorbers have demonstrated significant potential in stealth technologies due to their adaptability and capability to suppress the backscattering of electromagnetic (EM) waves. Developing high-performance absorbers for efficient wave capture and attenuation at terahertz (THz) frequencies remains a complex challenge, requiring innovative material and structural designs. This study presents a THz metamaterial absorber integrating a Zig-Zag-inspired frequency-selective surface (FSS) structure, enhancing absorption efficiency. The proposed -10 dB narrowband absorber at 0.14 THz is fabricated using cost-effective FR<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> and copper materials with a substrate thickness of 1.4 µm. The design achieves near-total absorption (approaching 100%) at a resonant frequency of 4.66 THz, with its absorption characteristics exhibiting high sensitivity to variations in structural parameters due to coupling effects within the zig-zag patterns. Additionally, the frequency-dependent effective permittivity, permeability, and impedance are extracted from reflection data to elucidate the underlying operational principles. The development of metamaterials with near-perfect absorption is essential for applications demanding high absorption efficiency and minimal reflectivity, such as antennas, stealth technologies, and THz sensing.