Pixellated Metasurface for Effective Absorption of Electromagnetic Wave at Desired Frequency

A optimization technique is used to design two pixel-lated metasurface absorbers to work in frequency ranges: 2-5 GHz and 6-8 GHz using CST Microwave Studio. The absorber is made up of copper patched pixels on FR4 substrate and a copper backing layer. Particle swarm optimization is used to decide the structural parameters of the absorber. Numerical results show a peak absorptance frequency of 2.85 GHz for metasurface 1 and 6.8 GHz for metasurface 2, with peak absorptance values of 0.98 and 0.99, respectively. The range of frequency over which the absorptance remains more than 0.9 is 200-MHz and 100-MHz for metasurface 1 and 2, respectively.