A broadband reconfigurable linear-to-circular polarizer/reflector based on PIN diodes

In this paper, a reconfigurable active metasurface is proposed to realize linear to circular polarization conversion and reflection by adjusting the states of PIN diodes. The structure is composed of a circular split ring and four sector-shaped circular patches; the PIN diodes loaded with the network feeder are designed to control the functions of polarizer and reflector. When diodes work in 'ON' state, the MS works as a linear-to-circular (LTC) polarizer, which can convert the linearly polarized waves into circularly polarized waves in 10.5-13.0 GHz with the relative bandwidth of 21.2%. When diodes work in 'OFF' state, the MS works as a reflector, and the co-polarization reflectance is greater than -1dB in 10.5-13.0 GHz, and the corresponding cross-polarization reflectance is less than -12.7dB. Polarization conversion rate (PCR) and absorbance (A) are both below 0.05. The microwave experiments are carried out in order to verify the simulation, and the measured results are in good agreement with the simulated results. We expect that our designed MS has the potential applications in in the fields of polarizers and wireless communication systems.