Limit Values Acquisition in Field Control Problems Using Information-Based Time-Reversal Technique

Despite numerous theories proposed to describe the near-field focusing problem, a non-negligible error still exists between the calculation result and the target, and the process involved is quite complicated. While the time-reversal (TR) algorithm has greatly reduced the problem’s complexity and improved accuracy under complex scenarios, it has limitations in problems involving large angles and complex area focusing. Both traditional and TR algorithms experience errors due to the loss of different types of information. In this communication, we propose an accurate focusing algorithm that combines TR with the vector fitting method. This algorithm effectively solves the limitations of traditional focusing algorithms in problems involving large angles, complex area focusing, and other scenarios. The proposed algorithm has the advantages of being fast, enabling global optimization, and not accumulating errors. To verify the accuracy of the algorithm, we design a tunable phase-modulated metasurface. By controlling different vias metallization, we obtain a 360° transmission phase shift with a transmission loss of less than 1 dB.