Wideband Circularly Polarized Slot Coupled Metasurface-Based Array Antenna

We present a 2 x 2 element array based on circularly polarized (CP) metasurface-based antennas fed by a sequential phase network. The single element consists of a microstrip-line-fed slot antenna coupled to a metasurface having 4 x 4 truncated corner square patches. The proposed array, with an overall size of 50 mm x 50 mm x 2.032 mm, resulted in an impedance bandwidth of 7.5 - 11.0 GHz (37.84%) for vertical bar S-11 < -10 dB and a CP radiation bandwidth of 8.4 - 10.7 GHz (24.1%) for axial ratio < 3. In addition, the antenna yielded a broadside left-hand CP radiation with a peak gain of 13.7 dBic and radiation efficiency greater than 90% within the CP radiation bandwidth.