A novel dynamic near-field focused system with Metasurface

A novel dynamic near-field focused system with a metasurface is proposed in this paper. It operates at 10 GHz and has 9 tunable focal spots. The proposed system consists of a 16 × 16 metasurface and an 8 × 8 array antenna. As a planar and compact structure, the array antenna serves as a feeding antenna in the proposed system, thereby significantly reducing the system profile. Moreover, the radiation field of the array antenna is controllable. By altering the amplitude distribution of the antenna aperture, the proposed system can achieve dynamic near-field focusing. Compared with other dynamic near-field focused designs loaded with RF switches, the proposed system significantly reduces the design complexity. To verify the feasibility of the design principle, the prototype has been simulated, processed, and tested. A wireless power transfer demonstration is also conducted. The results show that the proposed system improves the transmission coefficient by 5.5 dB to 12.7 dB compared to a fixed-focus system, validating its applicability in near-field energy delivery. Both simulation and testing results have revealed that the proposed system has good focusing and tunable performance.