Active Multifunctional Reflective Metasurface for Linear to Cross and Linear to Circular Polarization Conversion Applications

A low-profile reconfigurable reflective metasurface capable of dynamically switching polarization conversion functionalities is proposed in this work. To realize this, a single-layered metasurface comprising tapered rectangular metal strips oriented diagonally with a Z-shaped conducting strip in the middle and L-shaped metal strips along the corners is etched on a substrate backed by a conducting layer. A diode is positioned at the center of the diagonally oriented structure, and the switching is controlled using a radial stub-based DC biasing circuit. When the PIN diode is turned OFF, the tunable metasurface reflects cross-polarized waves in the frequency spectrum ranging from 12.3- 15.5 GHz, whereas, in the ON state, it converts linear polarized waves into orthogonally polarized waves from 14.83- 15.83 GHz, also converts linear to left-handed and right-handed circular polarization with an axial ratio of less than 3 dB across four distinct frequency bands. The 45° orientation of the metallic layer makes the structure polarization-independent and can be best used for radar cross-section (RCS) reduction and future wireless and satellite communications simultaneously.