A Reconfigurable Independent Dual-Polarization Control Reflectarray With a 9-μm-Thick Layer of Liquid Crystal

In this study, a reconfigurable independent dual-polarization control reflectarray antenna with 9-μ m-thick layer of liquid crystal is verified. This unit consists of two types of resonant structures (RSs) that respond to different linear polarizations. The liquid crystal layer acts as a variable capacitive medium, and the slot serves as an inductor and radiation aperture for the RS. Changing the voltage distribution between the two types of RSs will allow the unit to respond to electromagnetic waves of different polarizations. Experimental results show that the unit can achieve approximately 225° of continuous phase shift adjustment at 27.7 GHz for both X - and Y -polarized waves. Both polarizations have a figure of merit (FOM) exceeding 72°/dB. Further verification was performed by constructing a liquid crystal array containing 50× 50 units and selecting the middle 39 columns for control. The measured results show that horizontal and vertical polarization waves can be independently controlled to achieve a beam scan of ±40°. This work provides a good example for subsequent researchers studying thin liquid crystal layer reflectarray antennas.