Circularly polarized transmit-array with sequentially rotated elements in Ka band

A new design of circularly-polarized (CP) transmit-array is proposed for SATCOM applications with reduced axial ratio in the main beam direction. The unit-cell is formed by a linearly-polarized rectangular patch (receiving layer) connected to a CP patch (transmitting layer). The full-wave simulations show an insertion loss level (IL) of 0.2 dB at 30 GHz with a 1-dB bandwidth of about 9.4%. The sequential rotation of the CP patches has been implemented in order to further improve the polarization purity. The different distributions considered lead to a significant improvement of the cross polarization discrimination (XPD) with gain, side-lobe level and efficiency close to the configuration without rotations. Tilted-beam radiation patterns in the horizontal and diagonal planes will be also presented.