Reflectarray Antennas for Independent Dual Linear and Circular Polarization Control

This paper presents a dual-polarization reflectarray unit cell for wideband applications based on stacked Jerusalem crosses with a quarter-wavelength cell period. While unit cells with reduced interelement spacings can suffer from a reduction in phase range, the proposed cell exhibits a phase range of over 500° while maintaining a very independent response to two orthogonal linear polarizations. The unit cell is then integrated with a linear-to-circular polarizer to form a low profile fully planar structure which facilitates independent dual-circular polarization control using a modular design approach. Two prototypes, sized $13.3\lambda _{0}$ by $19.9\lambda _{0}$ at 20.5 GHz, are fabricated and measured, experimentally demonstrating the proposed concepts.