A New 1 Bit Electronically Reconfigurable Transmitarray

This article proposes a novel 1 bit electronically reconfigurable transmitarray, designed to facilitate digital two-dimensional beam scanning, boasting both high gain and a slim profile. The fundamental phase shifting unit of the transmitarray unit cell consists of a resonant cavity composed of a pair of orthogonal metal gates and dielectric layers, with a cross-sectional height of 0.17 λ. The middle layer of the phase-shifting unit is composed of circular gaps and C-shaped patches, and two diodes with opposite directions are loaded. By turning the diodes ON and OFF, current reversal is accomplished, allowing the unit to transition between its 0 and 1 states and achieve transmission-phase quantization. The unit’s minimal insertion loss is 0.37 dB in state 0 and 0.35 dB in state 1, respectively. In order to verify our design, we designed and processed a 16 × 16 transmitarray in the C-band. The simulated results are consistent with the experimental results. The experimental results show that the transmitarray can achieve ± 45° beam scanning on both the E-plane and H-plane, and the maximum gain is 20.59 dBi at 5 GHz, with an aperture efficiency of 20.5%.