A 1-bit Amplifying Space-Time-Coding Metasurface

To compensate the energy loss of traditional passive space-time-coding metasurface, an amplifying space-time-coding metasurface (ASTCM) is proposed in this work. The ASTCM can achieve more than 5 dB energy enhancement and over 20 dB dynamic amplitude manipulation with different control voltages of the amplifier chip. Furthermore, a stable 1-bit phase modulation is also realized through two oppositely arranged PIN diodes. For verification, a 6*6 metasurface array is constructed to realize flexible beam control by using different space-time-coding strategies. The proposed ASTCM exhibits amplifying capability and great beamforming performance, which may find critical applications in the field of wireless communication and radar systems.