Trung Nguyen Toan, Lee Dongju, Sung Hyuk-Kee, Lim Sungjoon
Appl Opt. 2016 Oct 10;55(29):8301-8307. doi: 10.1364/AO.55.008301.
This novel vertically and horizontally symmetric slotted-sector design aims to realize an angle- and polarization-insensitive metamaterial absorber. The unit-cell symmetries achieve polarization insensitivity, while an optimized slotted-sector inner angle enables angle insensitivity. Because the absorptivity of a metamaterial absorber depends on the incident angle and polarization, many researchers have studied angle- and polarization-insensitive unit cells. In this work, a novel vertically and horizontally symmetric slotted sector is proposed in order to realize an angle- and polarization-insensitive metamaterial absorber. The absorber performance is demonstrated with full-wave simulation and measurements. Angular sensitivity is studied for different slotted-sector inner angles. For an 85° inner angle, the simulated absorptivity exceeds 90% and the frequency variation is less than 1.2% up to 70° incidence. The measured absorptivity at 10.34 GHz is close to 98.5% for all polarization angles at normal incidence. As the incidence angle varies from 0° to 70°, the measured absorptivity at 10.34 GHz remains above 90% in the transverse electric mode.
这种新颖的垂直和水平对称开槽扇形设计旨在实现一种角度和偏振不敏感的超材料吸收体。单元胞的对称性实现了偏振不敏感性，而优化的开槽扇形内角则实现了角度不敏感性。由于超材料吸收体的吸收率取决于入射角和偏振，许多研究人员已经对角度和偏振不敏感的单元胞进行了研究。在这项工作中，提出了一种新颖的垂直和水平对称开槽扇形，以实现角度和偏振不敏感的超材料吸收体。通过全波模拟和测量展示了吸收体的性能。研究了不同开槽扇形内角的角度敏感性。对于85°的内角，模拟吸收率超过90%，在高达70°入射角时频率变化小于1.2%。在垂直入射时，对于所有偏振角度，在10.34 GHz处测得的吸收率接近98.5%。当入射角从0°变化到70°时，在横向电模式下，在10.34 GHz处测得的吸收率在70°时仍保持在90%以上。
