Wideband subwavelength-profile circularly polarised array antenna using anisotropic metasurface

A cost-effective solution for the performance enhancement of circularly polarised array antennas by using a thin metasurface is proposed. The array is considered as reconfigurable, where an antenna engineer can arbitrarily add the metasurface onto the original array according to application requirements. Once added, the new array forms a subwavelength cavity having a compact form factor of 1.63λ_o × 1.63λ_o × 0.07λ_o at 2.45 GHz. The array antenna is demonstrated to have remarkable enhancement on its performance metrics including boresight gain (12.8 dBic), axial-ratio bandwidth (46.5%) and 10 dBic gain bandwidth (24.4%). More interestingly, a sidelobe suppression level of 4.4 dB is achieved.