一种基于机械旋转的可重构超表面电磁开关设计

A Reconfigurable Metasurface EM Switch Based on Mechanical Rotating Structure

为了提高微波无线能量传输的效率以及灵活性,提出并设计实现了一款基于机械控制的可重构超表面电磁开关。该设计基于Pancharatnam-Berry(P-B)相位原理,是一种可机械旋转、具有波束控制能力的反射型超表面,可以直接应用于无线传输系统中。仿真与优化设计表明,对于垂直入射的右旋圆极化平面波,超表面能够实现同极化聚焦或散射两种可重构功能。将该超表面放在无线传输系统中的发射端可以形成反射面天线,从而对微波无线功率传输系统实现电磁开关的功能。实验结果表明,在设计的5.8 GHz附近,发射天线位于超表面焦点处时,通过调节超表面实现聚焦功能,可以使天线增益提高2.7 dBi;在无线传输系统中,可以通过超表面的引入实现电磁开关的功能。

In order to improve the efficiency and flexibility of microwave wireless power transfer(WPT), a reconfigurable metasurface based on mechanical control is proposed and implemented. The reflective metasurface is designed based on the Pancharatnam-Berry(P-B) phase principle and the phase control for beam steering is achieved by mechanically rotating the structure in the element. Thus the structure can be used for WPT. Simulations show that the metasurface performances either co-polarization focusing or scattering for right-handed circularly polarized plane wave with vertical incidence. Furthermore, by placing the metasurface in the reflector antenna of the transmitter in the WPT system, EM switch can be realized. Based on these studies, a WPT system is established. The experimental results show that when the transmitting antenna is located at the focal point of the metasurface and at the working frequency around 5.8 GHz, the antenna gain is increased by 2.7 dBi by adjusting the metasurface to focusing state, thus EM switch is achieved.