A Novel Amplitude Modulation Architecture via Time-Varying Programmable Metasurface for Wireless Communication Systems

Different from the traditional wireless communication systems, where both amplitude and phase components are used to provide a form of modulation, almost all of space time-modulated matesurface (MS) currently reported are modulated by phase components. In this paper we propose a new architecture of time-varying modulated MS based on two features. First, inspired by the idea of beamforming-like techniques that different digital sequences are added to the MS, in this way, the amplitude can be changed rapidly for modulation by holding the constant phase. Here, a pentagonal array-based MS is designed to achieve amplitude modulation (AM) by the use of on-off field programming gate array (FPGA) hardware. Second, a quasi-optical measurable scheme in the near-filed is used to show the phenomena and detect the measurements. To verify the ideas mentioned above, the simulations and measurements are carried out.