Reflectarrays with Ultra-Reconfigurable VO2 Unit-Cells for Next-Generation Communication Systems

This paper presents a novel VO2-based reconfigurable reflectarray that is validated using array theory models. Use of VO2, a phase change material, as the reflecting material allows for ultra-reconfigurability by modifying the shape and size of the conducting patches. The designed square patch unit-cell demonstrated a reflection phase shift in the order of 310°. To calculate the radiation pattern and the directivity of a deployable 20 by 20 element reflectarray, a procedure based on array theory is used. A directivity between 28-30 dBi is obtained with good beam-scanning performance within ±50° elevation angle at 32GHz. The proposed VO2-based reflectarray unit-cell can adjust the geometrical pattern of the patch, which enables the reflectarray to dynamically change its frequency of operation and steer its beam; therefore, our proposed design is electronically reconfigurable. The main advantage of this antenna is the versatility of reconfigurable states it can achieve in real-time.