Beam steerable terahertz antenna based on VO<sub>2</sub>

Abstract

To realize the diversified applications of terahertz wave, a new method to realize 2-bit (4 states) coding metasurface with only two hybrid units is proposed, which combines the phase transition characteristics of VO<sub>2</sub> and is different from the traditional metasurface. The metal wire threaded through the patch makes single-line control possible. The method of preparing the VO<sub>2</sub> thin film and the voltage control mechanism make the design more practical. The highlight of this design is that the fixed structure array can encode different state sequences and then tune the reflected beam. On this basis, a visual design is carried out for the calculation of the coding metasurface array antenna by MATLAB. The state sequence and radiation results are predicted by actively setting the operating frequency, beam deflection angle, etc., so as to achieve active adjustment. The system does not limit the unit structure and is universal to all arrays that meet the coding conditions. In addition, a deep neural network is introduced into the array arrangement, and the structure sequence is predicted by algorithm training and verified by numerical calculation and full-wave simulation. The results show that the proposed method is effective in beam deflection angle and structure arrangement. This study presents a new way of actively and flexibly controlling terahertz waves, which has potential applications in terahertz imaging, phase-controlled radar, communication and other fields.