On the Design of Resistive Reflectarray Elements having Both Amplitude and Phase Control

Unit cell elements in a conventional reflectarray are designed to provide required reflection phase while keeping the reflection amplitude constant. This paper introduces novel resistive reflectarray elements where reflective amplitude can also be controlled along with phase variations. Reflective amplitude is controlled by the value of resistivity (in Ω/sq) while reflective phase is controlled by the element dimensions. A resistive square patch and resistive circular patch designed respectively at 16 GHz and 22 GHz are presented. Both designs show amplitude and phase variations for different resistivity values and element dimensions. These resistive elements can be printed on a substrate along with conventional metallic reflectarray elements resulting in a simplified reflectarray design without adding much fabrication complexity.