Dual-polarized Unit-cell of Continuous Reflective Phase-shift for Reconfigurable Reflectarrays

This paper presents a Ku-band dual-polarized patch unit-cell of continuous phase shift for reconfigurable reflectarray antennas, which can twist the polarization of incident wave. This cross-polarized unit-cell can be applied in the folded reflectarray configuration for beam-scanning, and its performance is validated by the full-wave simulations under periodic boundary conditions. The scattered phase of the cross-polarized field varies continuously by approximate 300° as the capacitance in the varactor diodes is varied, and the magnitude of the cross-polarized field is higher than that of co-polarized field. The calculated results confirm that the dual-polarized multi-layer unit-cell consisting of dual-polarized H-shaped aperture coupled microstrips and vararctor-based reflection-type phase-shifter can be used as a reconfigurable reflectarray unit-cell to reflect the incident wave with a continuous phase shift after polarization twist.