Three-Phases Intelligent Reflectarray Antenna Using Liquid-Flow Control for Sub-6 GHz 5G Communications

This paper investigates the radiation characteristics of intelligent reflectarray antenna (IRA) for sub-6 GHz communications. The IRA uses polyamide helical shaped container unit-cells filled with liquid and supported by conducting ground plane. By employing electronic pumps that control the liquid injection through the containers. A parametric study on the unit-cell dimensions is optimized for 360 degrees phase variation range at 4 GHz. Three phase states 60°, 180°, and 300° are used to design $11\times 11$ IRA arrangement to reduce the design complexity and proper radiation efficiency. A conical horn placed at 550 mm is used to illuminate the IRA. A broadside directive beam is radiated with peal gain 21.2 dBi compared to 21.6 dBi for continuous-phase IRA. Beam switching from 0° to 60° is achieved via changing the liquid flow through the structure keeping the physical structure fixed.