This study presents a lightweight metasurface microwave absorption filter (MMAF) designed for low-frequency stealth applications in the L-band. The metasurface is optimized using a genetic algorithm to achieve broadband absorption at subwavelength thickness. The fabricated MMAF consists of a glass fiber-reinforced plastic layer, a metasurface layer, and a dielectric layer with a size of 30 × 30 cm². It maintains a reflection coefficient below −10 dB in the frequency range of 1.01–1.78 GHz. Experiments using small MMAFs measuring 15 × 15 cm² confirmed stable performance after composite molding. In addition, the results from small MMAFs configured in a 2 × 2 array were similar to those of the 30 × 30 cm² structure. These results highlight the potential of the MMAF for scalable deployment on curved or segmented surfaces, expanding its applicability to various stealth platforms.

This study proposes design and fabrication methods for an electromagnetic metasurface absorber (MA) that absorbs electromagnetic waves using a metasticker attached on a dielectric substrate blocked by a copper sheet. To guarantee a high design freedom as well as make the absorption bandwidth (BW) as broad as possible, a square-fractal ring is chosen as the metapattern, and its design is optimized using a genetic algorithm. To fabricate the square-fractal rings in a simple manner, an indium-tin-oxide film is cut by using a laser-cutting machine. Then, the metasticker is fabricated by assembling the metapatterns on a double-sided adhesive film which could be attached on the dielectric substrate using the opposite side of the film. From measured results of the finalized MA of which damaged regions caused by the laser-cutting process are compensated in the design process, a broad $-10$ dB reflectance BW is confirmed from 4.39 to 7.51 GHz of which the fractional BW is 52.44% for the normal incidence. Moreover, a fractional BW of 4.35% is measured in a wide incident angle range from $0°$ to $60°$ for both the transverse electric and the transverse magnetic polarizations simultaneously.

한국전자파학회논문지 (The Journal of Korean Institute of Electromagnetic Engineering and Science)