Broadband Polarization-Reconfigurable Converter Using Active Metasurfaces

Polarization control of electromagnetic (EM) waves is vital in imaging and wireless communication systems. In this communication, we propose a broadband polarization-reconfigurable converter (BPRC) based on active metasurfaces, which can achieve polarization-reconfigurable conversion under both linear-polarization (LP) and circular-polarization (CP) incident waves in wide bands by changing the states of the p-i-n diodes. The BPRC is composed of three-layer metal patches, three-layer dielectric substrates, and p-i-n diodes. When the p-i-n diodes are in the OFF-state, the LP and CP incident waves can be converted into cross-polarization and co-polarization reflected waves, respectively. Whereas when the p-i-n diodes are changed from OFF-state to ON-state, the LP and CP incident waves can be converted into co-polarization and cross-polarization reflected waves, respectively. The conversion ratio is higher than -1 dB in the frequency range of 7.4-12 GHz, with a relative bandwidth of 47.4%. Furthermore, the simulated and experimental results were in good agreement, and thus verified the feasibility of the BPRC, which will find promising applications in wireless communication systems.