Low Thickness and Wideband Triple-Layered Transmitarray Unit-cell Design

This paper presents a design of ultra-low thickness unit-cells for wideband transmitarray antennas. The unit-cells have three metallic layers and are based on multi-layer frequency selective surfaces (M-FSS) that allows simple design and fabrication process. Moreover, a polarization rotation technique is used in this unit-cell design to achieve a very wide transmission bandwidth and large transmission phase range. Simulations have been conducted to optimize the unit-cell dimensions for eight different phase states around the center frequency of 12.5 GHz. The simulated results demonstrate that the unit-cell exhibits a common 1-dB transmission magnitude bandwidth of 15.2% from 11.8 GHz to 13.7 GHz. Good radiation patterns and high aperture efficiency are also reported by measuring a transmitarray prototype.