1-bit Reconfigurable Metasurface Unit Based on Resonant Coupling

Abstract

In this paper, a reconfigurable metasurface unit based on the resonant coupling between the main reflector and the parasitic reflector is proposed to address the existing problems of narrow band and high loss for 5.8GHz industrial scientific medical (ISM) application. The metasurface unit we have designed consists of two main parts, the main reflector and the parasitic reflector. The design of the main reflector is based on the microstrip antenna theory, while the design of the parasitic reflector is based on the meander technique of microstrip antenna theory, which allows us to design the metasurface unit to achieve a broadband and low loss. The phase control of the reflected wave can be achieved by controlling the operating mode of the PIN diode connected to the parasitic reflector. When the PIN diode is on the parasitic reflector is resonantly coupled to the main reflector, while when the PIN diode is off the parasitic reflector is not resonantly coupled to the main reflector, resulting in a 180° phase difference between the reflected waves in the two states. The results show that When the PIN diode is on, the loss in the metasurface unit is −1.747dB; when the PIN diode is off, the loss in the metasurface unit is −0.506dB. As the PIN diode changes its operating state, reflected wave will have a phase difference of nearly 180° in the 5.662-5.945 GHz band.