Ultra‐Wideband Simultaneous Manipulations of Fundamental and Harmonic Waves Based on Space‐Time Coding Metasurface: Basic Principles and mmWave Applications

Abstract A 2‐bit millimeter‐wave (mmWave) space‐time coding metasurface (STCM) based on an innovative theoretical mechanism and encoding strategy to boost the performance of wireless communications is proposed. Specifically, this metasurface can switch between four different modes by controlling the working states of the active components loaded on the metasurface element. Combined with a simple, efficient, and robust mechanism and encoding strategy, it achieves arbitrary phase controls of the fundamental and harmonic frequencies over an ultra‐wideband range. Based on these developments, a single‐aperture, multi‐channel mmWave wireless communication system is constructed that basically spans the entire V‐band. It is demonstrated that different data are transmitted under the quadrature phase shift keying modulation scheme at the fundamental and harmonic frequencies, with an operating bandwidth exceeding 25 GHz. Furthermore, the research has achieved an ultrafast single‐aperture communication rate, while seamlessly integrating information modulation and beamforming into the system. The proposed mmWave STCM‐based communication architecture, both compact and miniaturized, offers an efficient and low‐complexity solution for achieving comprehensive coverage, affordability, high capacity, and reliable communications in the next‐generation wireless networks.