Combined L-shaped Broadband Metasurface Absorber

This paper focuses on the absorber that has the greatest impact on the response performance in terahertz detector structures. By combining L-shaped resonant structures, a dual-frequency metasurface absorber is proposed, achieving up to 100% perfect absorption at two resonant points, 103 GHz and 51 GHz. At a center frequency of 103 GHz, it achieves an absorption of over 80% within a 9.69 GHz bandwidth. The metasurface uses Al2O3 as the dielectric layer, compatible with standard printed circuit board (PCB) technology, significantly reducing production cycles and manufacturing costs. The absorber achieves a certain degree of polarization insensitivity through the rotation and combination of the L-shaped basic structure.