Folded Transmitarray Antenna Using Low Thickness Transmitarray Unit-Cells

This paper presents a design of a folded transmitarray antenna using ultra-thin unit-cells. The unit-cell structure comprises three metallic layers printed on two identical substrates. The unit-cell allows a polarization rotation of the transmitted wave compared to the incident wave. It can provide a very large transmission bandwidth with very low loss, smaller than 0.5 dB. The unit-cell structure also enables a simple fabrication process and reduces cost. To achieve four different phase states at a central frequency of 12 GHz, the unit-cell dimensions were optimized through simulations. The simulated results indicate that the unit-cell achieves a common 0.5-dB transmission magnitude bandwidth of 40.8%, spanning from 11.0 GHz to 15.9 GHz. A folded transmitarray has been designed. The simulated results show that the aperture efficiency achieves 42.5% at 12.5 GHz.