A Wide-Angle and High-Efficiency Reconfigurable Reflectarray Antenna Based on a Miniaturized Radiating Element

A wide-angle reconfigurable reflectarray antenna (RRA) utilizing a miniaturized ring patch that can be efficiently controllable with a single bit is designed and experimentally verified. Based on the adoption of miniaturized radiating element and the elaborate study to optimize quantization efficiency considering reference phase and asymmetric phase difference, highly directive beam scanning is achieved in a wide ±60° range in both the
$H$
- and
$E$
- planes. Furthermore, the feeding structure to minimize focal diameter ratio (F/D) and maximize feeding efficiency such as illumination and spillover Efficiencies is studied, resulting in a low profile configuration with F/D=0.36. The fabricated RRA prototype was measured at 9.85 GHz (X-band) with the highest aperture efficiency of 28% and a 1 dB gain bandwidth of 530 MHz, respectively.