Broadband actively amplifying metasurface for reconfigurable amplitude enhancement

Amplifying metasurfaces have emerged as an efficient approach to realize energy enhancement. Here, we propose a broadband amplifying metasurface by combining amplifying circuits with elaborately designed H-shaped slotted square patch antennas. A prototype is fabricated and experimentally verified. The measured peak cross-polarized reflection coefficient is 15.1 dB and the operating band ranges from 3.69 GHz to 4.79 GHz, with a relative bandwidth of 25.9%, which agree well with simulation results. The proposed metasurface shows potential uses in real-word applications, such as dynamic radar cross section (RCS) control and wireless communication systems.