Numerical study of a broadband metamaterial absorber using a single split circle ring and lumped resistors for X-band applications
Nguyễn Thị Hòa, Thi Quynh Hoa Nguyen, Thi Kim Thu Nguyen, Thi Kim Thu Nguyen, Thanh Nghia Cao, Hugo Nguyen, Long Giang Bạch
Abstract
We report a numerical study on the design of a broadband metamaterial absorber (MMA) with a single layer of metal–dielectric–metal based on an FR-4 substrate for X-band applications. The MMA structure consists of a periodic array of a split circle ring and lumped resistors coupled within split segments. The MMA structure achieves a broadband absorption response in the frequency range of 7.8–12.6 GHz with an absorptivity of above 90% under normal incidence for all polarization angles. The absorptivity remains above 70% in the frequency range of 6.8–11.8 GHz at wide incident angles from 0° to 30° for both transverse electric and transverse magnetic polarizations. The physical mechanism of the absorber is explained by the electric and the surface current distributions that, in turn, are significantly affected by magnetic resonance.