Broadband Sequential Rotation Array of Circularly-Polarized Metasurface Antennas at Ka-Band

A low profile and broadband sequential rotation array of circularly-polarized metasurface antenna elements at Ka-band is proposed in this paper. The antenna element includes a circularly-polarized patch antenna loaded with a strongly truncated metasurface, which is fed through a coupling aperture. An array of four elements is further constructed using the sequential rotation technique to achieve broadband circularly-polarized radiation at broadside. The final optimized and fabricated antenna array exhibits an
$S_{11} < -10\ \text{dB}$
bandwidth of 28.7% and an axial ratio < 3 dB bandwidth of 27.2%. In addition, within this bandwidth, the proposed structure yields a broadside gain of 9.8 dBic with a fluctuation of less than 2 dB. It is a promising candidate for wideband millimeter-wave wireless and satellite communications.