XOR-Logic Phase Coding Programmable Metasurface for Low Power-Consumption Systems.

Programmability greatly enhances the degree of freedom to manipulate electromagnetic (EM) waves dynamically and lays crucial foundation for intelligent applications of metasurfaces. However, the traditional programmable metasurfaces need complicated biasing networks to control m×n digital meta-atoms independently to fulfill the reprogrammable functions in real time, which also results in large power consumption to drive the metasurface. To alleviate this problem, we propose an XOR-logic phase coding programmable metasurface to reduce the complexity of biasing network from m×n to m+n, which can reduce the power consumption significantly. The XOR-logic phase coding is achieved by path symmetry of surface currents on a Pancharatnam-Berry meta-atom loaded with two PIN diodes. By controlling 2×m×n PIN diodes on the whole metasurface in row-column manner, only m+n biasing lines are required to switch 0 and 1 states of all meta-atoms independently. As the proof of concept, a prototype of the XOR-logic phase coding programmable metasurface is designed and fabricated. Both simulation and measured results verify the reprogrammable functions of beam scanning and multi-beam scattering. This work provides a new type programmable metasurface with simple architecture and low power consumption, which will find wide applications in intelligent systems such as next-generation wireless communication, Internet of Things, and radar.