Polarization-diversity backscatter communication based on programmable information metasurface

Backscatter communication (BC) is a low-power technology that transmits data by reflecting ambient RF signals. Conventional BC, based on antenna impedance modulation, suffers from low data rates and poor interference resistance. Programmable information metasurface (IMS) offers a breakthrough by enabling precise wave control. This article presents a PIN-diode-based IMS for polarization-diversity backscatter transmission. It performs full-space secondary modulation, converting horizontally polarized incident waves into ±45° polarized signals. Operating at 5 GHz, the system uses two polarization channels with BPSK and BASK modulation to transmit the same data, achieving 2 Mbps with improved reliability through diversity. The proposed system exhibits low power consumption, strong interference resistance, and high stability, making it suitable for IoT applications such as smart healthcare and environmental monitoring.