Direct Transmission of Digital Message via Programmable Coding Metasurface

TLDR

Modern wireless systems convert digital data to analog, mix to microwave, and transmit via a chain of modulators, mixers, amplifiers, filters, and antennas, yet this basic architecture has remained unchanged for three decades. The authors propose transmitting digital information directly through a programmable coding metasurface. The metasurface, built from binary “0” and “1” units with opposite phase responses, modulates data into its radiation pattern under a feeding antenna, enabling multiple receivers to decode the signal, and a prototype was constructed to validate the approach. This architecture eliminates the need for digital‑analog converters and traditional microwave components, and experimental results demonstrate its potential for secure communications.

Abstract

In modern wireless communications, digital information is firstly converted to analog signal by a digital-analog convertor, which is then mixed to high-frequency microwave to be transmitted through a series of devices including modulator, mixer, amplifier, filter, and antenna and is finally received by terminals via a reversed process. Although the wireless communication systems have evolved significantly over the past thirty years, the basic architecture has not been challenged. Here, we propose a method to transmit digital information directly via programmable coding metasurface. Since the coding metasurface is composed of '0' and '1' digital units with opposite phase responses, the digital information can be directly modulated to the metasurface with certain coding sequences and sent to space under the illumination of feeding antenna. The information, being modulated in radiation patterns of the metasurface, can be correctly received by multiple receivers distributed in different locations. This method provides a completely new architecture for wireless communications without using complicated digital-analog convertor and a series of active/passive microwave devices. We build up a prototype to validate the new architecture experimentally, which may find promising applications where information security is highly demanded.