Polarization-insensitive phase-modulated metasurface using single thermally stimulated vanadium dioxide chip.

Considering that typically more than two pin diodes or other tunable elements are required in the unit cell of polarization-insensitive reconfigurable metasurfaces (RMs), this paper proposes a new approach to design a polarization-insensitive RM unit using only one VO2 chip. A polarization-insensitive phase-modulated metasurface (PMM) using single VO2 chip is presented. The surface layer is composed of an outer ring and an inner cross, with a VO2 chip loaded at the connection of the cross. As the VO2 chip can be connected with the metal patch on all sides, only one VO2 chip is used in this polarization-insensitive design. By thermally controlling VO2 chips switch between low-resistance and high-resistance states, the PMM achieves a 1-bit phase shift within 180° ± 37° from 7.85 to 15 GHz. A prototype is fabricated and measured, and the measured results have verified the correction of the design and analysis of the designed PMM.