An Analysis of Dual-Band Octagonal Ring Metamaterial Absorber

Simulation of a dual-band octagonal ring metamaterial absorber is presented in this paper. With absorbance characteristics at resonated frequency in C-band and X-band, the proposed structure has polarization insensitive up to 70° and 90° of incident angle. By using CST Microwave Studio, designed and simulated structure shows minimum return loss of 11.31 dB and 16.4 dB with the absorbance of 0.926 and 0.977 at 6.21 GHz and 10.5 GHz respectively. The proposed structure also has been analyzed in terms of the different substrate with different permittivity and thickness which shows the different characteristics. FR-4 substrate shows the higher bandwidth while RO3010 shows the higher absorbance rate for octagonal ring metamaterial absorber. The thickness of the substrate also gives an effect to the absorbance quality, where the thick substrate would have lower absorbance depending on the material permittivity. With the latest technology, octagonal ring metamaterial absorber gives the potential to be applied in stealth applications of surveillance and defence.