PIN Diodes Based Bi-Functional Metasurface With Polarization Conversion and Full Reflection Characteristics

We propose a true bi-functional metasurface with polarization converter/full reflection functionalities. By changing the state of PIN diodes (ON and OFF state), the developed structure may be used not only as a metallic ground sheet in addition, as a polarization converter. During OFF state of diodes, the structure can convert linear-polarized (LP) incident waves into orthogonal LP reflected waves in the two different bands of 3.46-4.28 GHz and 8.55-11.32 GHz with over 90% polarization conversion ratio. In addition, the incident LP waves also can be adequately converted into circular-polarized (CP) wave in the frequency range from 5.53-6.67 GHz. However, during the ON state of diodes, the developed structure act as a reflecting metal plate with magnitude of co-polarized reflection is over -1.5 dB from 1.00-15.00 GHz. The proposed bi-functional metasurface has many potential for developing reconfigurable multi-polarization converter for polarization control microwaves devices.