A Wideband, Low-Profile, and 1-Bit Beam-Scanning Reflectarray at X-Band

A 1-bit reconfigurable reflectarray with wide-angle scanning range from 9.15 GHz to 10.9 GHz is proposed in this paper. To allow wideband coverage while maintaining low profile, the unit cell loaded by one p-i-n diode was designed to optimally increase element bandwidth, i.e., the bandwidth for reflection-phase difference within 180° ± 20° between the diode’s on- and off-states. To achieve greater degree of structural optimization and improvement for aperture efficiency, p-i-n diodes and the biasing network were deployed on the opposite side of phasing elements. A $10 \times 10$ reconfigurable reflectarray was prototyped and can experimentally scan its main beam from +40° to −40° at frequencies of 9.15, 10, and 10.9 GHz with peak gain of 14.97 dBi. The measured 1-dB bandwidth is 10.8%.