Younis Fatima, Khan Owais, Ahmad Jawad, Qasim Muhammad Javed, Luo Heng, Wang Shiliang
School of Physics, Central South University, 410083, Changsha, China.
School of Electronics Information, Central South University, 410083, Changsha, China.
Sci Rep. 2025 Aug 12;15(1):29455. doi: 10.1038/s41598-025-12790-1.
This study presents a tri-band metasurface absorber (MSA) based on a dual elliptical geometric resonator with an enclosed circular structure. Designed on a low-cost FR-4 substrate, the proposed MMA consists of an elliptical resonator with a strip line shape at the top and a full ground plane at the bottom. To achieve tri-band absorption, a multi-resonance topology incorporating two symmetrical elliptical resonators and a metallic strip is optimized. The unit cell measures 5.8 × 5.8 × 1.5 mm³ (0.54λ₀ × 0.54λ₀ × 0.140λ₀ at the lowest frequency of 28 GHz). A detailed parametric analysis is conducted to examine the impact of the unit cell's geometric variations on the reflection and absorption coefficients. Rotating the metallic strip by 90° in the multi-resonant metasurface structure enabled the transition from single-band to tri-band absorption. Under normal incidence, the proposed MMA exhibits three absorption peaks at 28 GHz, 33 GHz, and 38 GHz, with high absorption rates of 99%, 98%, and 99%, respectively. The MSA is further analyzed under transverse electric (TE) and transverse magnetic (TM) polarized waves, demonstrating polarization-insensitive behavior. The unit cell response is also investigated using an equivalent circuit model and surface current analysis. To validate the design, the unit cell is extended into a metasurface array and fabricated for experimental evaluation. The measured results confirm absorption rates of 97%, 95%, and 99.6% at 28 GHz, 33 GHz, and 38 GHz, aligning well with simulated predictions. The combination of high absorption efficiency, polarization stability, and low-cost fabrication makes the proposed MSA suitable for tri-band 5G/6G millimeter-wave applications.
本研究提出了一种基于具有封闭圆形结构的双椭圆几何谐振器的三频段超表面吸收器（MSA）。所提出的MMA设计在低成本的FR-4基板上，由顶部为带状线形状的椭圆谐振器和底部的全接地平面组成。为了实现三频段吸收，对包含两个对称椭圆谐振器和一条金属带的多谐振拓扑结构进行了优化。单元尺寸为5.8×5.8×1.5 mm³（在最低频率28 GHz时为0.54λ₀×0.54λ₀×0.140λ₀）。进行了详细的参数分析，以研究单元几何变化对反射和吸收系数的影响。在多谐振超表面结构中将金属带旋转90°可实现从单频段到三频段吸收的转变。在垂直入射下，所提出的MMA在28 GHz、33 GHz和38 GHz处呈现三个吸收峰，吸收率分别高达99%、98%和99%。在横向电场（TE）和横向磁场（TM）极化波下对MSA进行了进一步分析，表明其具有极化不敏感特性。还使用等效电路模型和表面电流分析研究了单元响应。为了验证设计，将单元扩展为超表面阵列并进行制造以进行实验评估。测量结果证实了在28 GHz、33 GHz和38 GHz处的吸收率分别为97%、95%和99.6%，与模拟预测结果吻合良好。高吸收效率、极化稳定性和低成本制造的结合使得所提出的MSA适用于三频段5G/6G毫米波应用。
