Novel 1-bit elementary cell for reconfigurable reflectarray antennas

This paper presents a novel reconfigurable radiating element for the realization of large beam-steering reflectarrays. The proposed elementary cell consists of a square patch coupled to a phase shifting circuit realized in slot-line technology, with 1-bit of phase resolution (0°/180°). Reconfigurability is obtained by mounting two PIN-diodes on the slot-line circuit. Dimensions of patch and slot-lines on phase shifting layer are optimized using an equivalent model of the structure based on antenna-filter- antenna (AFA) principle of operation. The key aspects of the design, modeling, and characterization of the element are addressed in this paper. The principle of operation, and the modeling approach of the cell have been experimentally validated with a dedicated measurement setup using a proof-of-concept board made of 16×16 elementary cells in hardwired configuration.