This article presents a metamaterial based on a modified asymmetric circular split ring resonator for absorber applications in the microwave regime. This metamaterial absorber (MMA) exhibits four absorption peaks to cover C, X, and Ku band applications. The MMA unit cell is formed on a low-cost FR4 substrate with electrical dimensions of 0.106 λ₀ × 0.106 λ₀, for which wavelength, λ₀ is calculated at 4.1 GHz. The resonator of the unit cell is structured with three concentric intercoupled circular split rings with dimensions modified to obtain maximum absorption peaks of 97.9%, 99.1%, 99.5%, and 99.95% at 4.1, 6.86, 11.3, and 13.45 GHz, respectively. Metamaterial and absorber properties are investigated in the analysis of the surface current, electric, and magnetic fields. The unit cell exhibits single negative metamaterial properties with an effective medium ratio (EMR) of 9.15 and quality factor (Q factor) greater than 20. Beyond that, the equivalent circuit of the MMA unit cell is modeled and validated by comparing S₁₁ obtained from Advanced Design System (ADS) and CST software. The MMA array’s absorption properties are also examined in the simulations. Measured results of the unit cell and array correspond well with the result of simulation in terms of absorption at intended frequencies. Given its good EMR, superior quality factor, and high maximum absorption, the MMA can be a good candidate for a multiband absorber in microwave applications like sensing, detecting, notch filtering and to decrease the indirect reverberation and reflections caused by the metallic part of the radar and satellite antennas.

本文介绍了一种基于改进的不对称圆形开口环谐振器的超材料，该材料可用于微波领域的吸收器。这种超材料吸收剂（MMA）表现出四个吸收峰，可涵盖C，X和Ku波段应用。形成在MMA单元电池的低成本FR4基板上的0.106λ电尺寸₀  ×0.106λ ₀，为此波长，λ ₀是在4.1 GHz下计算的。单位单元的谐振器由三个同心的相互连接的圆形开口环构成，并对其尺寸进行了修改，分别在4.1、6.86、11.3和13.45 GHz时分别获得97.9％，99.1％，99.5％和99.95％的最大吸收峰。在分析表面电流，电场和磁场时会研究超材料和吸收体的特性。晶胞表现出单一的负超材料特性，有效介质比率（EMR）为9.15，品质因数（Q因子）大于20。除此之外，通过比较S ₁₁对MMA晶胞的等效电路进行建模和验证从高级设计系统（ADS）和CST软件获得。模拟中还检查了MMA阵列的吸收特性。单位晶胞和阵列的测量结果在预期频率下的吸收方面与模拟结果非常吻合。鉴于其良好的EMR，卓越的品质因数和高最大吸收率，MMA可以成为微波应用中多频带吸收器的良好候选者，例如传感，检测，陷波滤波，并减少由金属的金属部分引起的间接混响和反射。雷达和卫星天线。