A Dual Band 28/38 GHz Metamaterial Absorber for 5G Applications

A dual-band metamaterial absorber (MMA) for fifth-generation (5G) applications is discussed in this work. The suggested absorber works at frequency bands of 28 GHz and 38 GHz. The suggested MMA unit cell with a size of 5.8 mm × 5.8 mm (0.54 λ0 × 0.54 λ0 at 28 GHz) is designed on 1.5 mm (0.14 λ0) low-cost FR4 substrate and composed of two metallic ring resonators. The suggested MMA is investigated to validate its performance for different polarization for transverse electric (TE) and transverse magnetic (TM). Both normal and oblique angles are studied. The MMA has a simple structure with a compact size. Different parameters such as the currents, electric field distributions, and normalized impedance are studied. The array of 10 × 10 unit cells is utilized to verify the simulated outcomes. The suggested MMA is fabricated and tested, and its outcomes are compared to the simulated outcomes. The MMA is operated at dual bands 28/38 GHz with high absorption rates of 98 and 98.4%, respectively, under the normal incidence for both outcomes. A good matching between the two outcomes is observed, which supports the MMA for 5G applications.