A Low-F/D Wideband Transmitarray Antenna

In this paper, a wide 3-dB gain bandwidth transmitarray (TA) antenna with low focal length to diameter ratio (F/D) is presented. The TA comprises four identical metasurface layers, and the metasurfaces are printed on thin dielectric substrates, which are separated by air gaps. The unit cells of the metasurfaces are constructed by etching slots on the metal layers, which include a serrated crevice and two disjunct slots. The F/D of the TA is designed as 0.48 to accommodate the applications required low profiles. A TA is constructed by arranging high transmission elements at the center and the other elements in the external of the aperture. A transmitarray antenna (TAA) operating at 9 similar to 13 GHz is designed by applying a horn antenna to the TA, which achieves a measured 1-dB gain bandwidth of 10.5% (3-dB gain bandwidth of 23.3% and measured maximum gain of 22.48 dBi at 10.5GHz) and a maximum measured aperture efficiency of 38.4%. Compared to the reported works, the proposed TA has outstanding F/D and wide 3-dB gain bandwidth.