Compact wideband metasurface-based circularly polarized antenna for Ka-band phased array

A metasurface-based compact wideband circularly polarized (CP) antenna is proposed. The antenna is composed of dual-layer overlapping metasurface coupled by cross-slot through single series stripline feed. A 64-element metasurface-based CP phased array with a scan angle up to 30 degree off the boresight direction shows the gain higher than 22 dBic, active reflection coefficient less than −9 dB, axial ratio less than 3 dB, and side-lobe levels less than −10 dB from 28 GHz to 31 GHz.