Design of programmable beam splitting metasurface

Metasurface has been applied as one critical platform for electromagnetic modulation devices. Here, a programmable metasurface loaded with positive-intrinsic negative (PIN) diodes is proposed to realize dynamic switching of arbitrary multi-beam. Furthermore, the multi-beam coding sequence is optimized by a genetic algorithm (GA) to achieve dual- to nine-beam with different scattering directions. As a proof of concept, a programmable metasurface prototype that operates around 8 GHz is designed and fabricated to be tested in far-field measurements. The beam splitter has been verified by theoretical analysis and numerical simulation to have a power efficiency of over 70%. In the measurement system, multi-beam splitting phenomena are obtained using DC control of the PIN diodes "on" and "off", which is consistent with the simulation results. The proposed beam splitter can be designed with real-time multi-beam switching and intelligently provides coding sequences with multiple directive angles, thus providing potential benefits for next-generation antennas.