Wideband Ultralow-profile Folded Transmitarray Based on Metasurface

This paper proposes a novel design strategy for wideband ultralow- profile Folded TransmitArray (FTA) antenna using metasurfaces. It consists of two kinds of metasurfaces and an open waveguide antenna as the feed source. The bottom metasurface is applied to transforming the linearly polarized wave coming from feed antenna into its cross- polarized reflected ones. Meanwhile, the top metasurface is capable of reflecting one linearly polarized wave and transmitting the other orthogonal counterpart. With smart design, the proposed FTA can reflect the electromagnetic wave back three times between two metasurfaces and realize high gain performance within a wide frequency band, and its profile height is decreased to 1/ 4 that of conventional transmitarray. The simulated and measured results are basically consistent, which demonstrates a 3 dB gain bandwidth of 19.6% (9.2 similar to 11.2 GHz), a peak gain of 21 dBi and a peak aperture efficiency of 30% at 9.6 GHz. The proposed design offers a new avenue for wideband low profile array antenna.