A Wideband Metal-Only Transmitarray With Two-Layer Configuration

This letter presents a novel wideband metal-only transmitarray (TA). Up to date, existing works on TAs use at least three layers spaced by air gaps. Compared these designs, the presented TA has only two and can realize full 360 phase shift with low insertion loss wide bandwidth. The unit cell consists of metal connected post converts linearly polarized incident wave orthogonal direction. type configuration increases mechanical robustness surface improves alignment accuracy layers. Through mirroring slots bottom layer, electrical field transmitted is rotated 180°, which equivalent 180°. Using this characteristic simultaneously adjusting lengths slots, continuously 360° range obtained. To verify design concept, prototype consisting 256- cells was designed, fabricated, measured. experimental results show that 14.6% 1 dB gain bandwidth 47.6% aperture efficiency 8.5 GHz. proposed advantages wideband, no dielectric loss, robust performance.