Reconfigurable Linear-to-Linear Polarization Conversion Metasurface Based on PIN Diodes

A reconfigurable linear-to-linear polarization conversion metasurface (Re-PCM) based on positive-intrinsic-negative (PIN) diodes is proposed, which can be reconfigured between the conversion mode and the reflection mode by switching the loaded PIN diodes. The unit cell of the Re-PCM consists of two slotted metal square rings and bias lines, which are all etched on a substrate backed by a metal ground. In the conversion mode, the Re-PCM reflects linearly polarized incident waves with 90° polarization rotation. The simulated results show that the polarization conversion ratio is more than 88% over 3.39-5.01 GHz for x-polarized and y -polarized normally incident waves. In the reflection mode, it exhibits total reflection characteristic like a metal plate. The magnitude of co-polarization reflection is over -1 dB from 3.83 to 4.74 GHz. The physical mechanism and equivalent circuit of the Re-PCM are analyzed. To validate the simulation, a prototype of the Re-PCM is fabricated and measured. Reasonable accordance between the simulated and measured results is obtained.