Scattering terahertz wave regulation of coded metasurface based on phase change material

Abstract By using the combination of resonant plasma-coded metasurface and phase change material GST, a tunable cell structure was designed. Using these units, the encoded metasurface was constructed to achieve different beam regulation functions. The designed unit structure consists of coding particles displaying two characteristics respectively. Particle A can control the abnormal scattering angle in the amorphous state of GST. Particle B can realize the amplitude regulation in both crystalline and amorphous states of GST. By introducing Fourier convolution principle in digital signal processing, the multi-angle beam modulation of coded metasurface can be realized. The introduction of phase change material leads to a tunable function of designed coded metasurface. This method of beam directed scattering is expected to play a role in human physiotherapy of electromagnetic wave.