A Metasurface-Based Folded Transmitarray Antenna With Ultralow Profile

A metasurface-based ultralow profile folded transmitarray antenna (FTA) is proposed. An integrated feed source, a reflective polarizer, and a polarization-selective metasurface together form the FTA. Both the reflective polarizer and the polarization-selective metasurface have stable EM responses over a wide angle. The integrated feed source is a rectangular waveguide antenna that is used to provide a low-gain and wide-coverage beam. The final design of the FTA has an ultralow profile with height-to-diameter (H/D) ratio of only 0.16 while maintaining good radiation performance. The measured results include a peak gain of 28.82 dBi at 28.2 GHz with an aperture efficiency of 35.2% and a 3-dB gain bandwidth of 6.8%. The proposed FTA can find significant applications in radar systems and satellite communications.