A New Compact Quad-Band Metamaterial Absorber Using Interlaced I/Square Resonators: Design, Fabrication, and Characterization

This paper presents the design and analysis of a new compact quad-band metamaterial absorber (MMA). The proposed structure is constructed as an array of 12 × 13 unit cells, each one is based on a combination of interlaced I/square resonators supporting four distinct resonant frequencies. The proposed metamaterial unit cell is printed on FR-4 substrate with thickness 1.5 mm and size 20 mm × 20 mm. The MMA structure exhibits four distinct absorption peaks at 2.248, 2.878, 4.3 and 5.872 GHz with absorption rates of 96, 93, 93, and 95 %, respectively, under normal incidence. This design achieves a negative permittivity and permeability that is applicable for S-band and C-band operating frequencies. The MMA unit cell structure has a 3-dB bandwidth of 78, 89, 144 and 202.6 MHz. The proposed structure has compactness of 0.15 λ0× 0.15 λ0 with thickness of 0.0112 λο, where λ0 is the free-space wavelength with respect to the lowest resonance frequency (2.248 GHz). The input impedance, surface currents and electric field distributions are shown to illustrate the mechanism of the structure. The design has been fabricated showing a good agreement between simulated and measured results. The proposed absorber structure can be used in different applications such as electro-magnetic protections, as well as military and medical applications. All simulation results are performed using the Computer Simulation Technology (CST), Microwave Studio 2018 software and Mathwork simulation tool MATLAB ver. 2011.