Design of Dual-Circular Polarized Planar Ka-Band Antenna Array Element For SATCOM Receivers

The design of an antenna array element with dual-circular polarization (CP) suited for SATCOM receiver modules operating in the Ka-band specifically in 19.2 GHz–21.2 GHz is presented. The unique element design integrates the conventional aperture coupled square patch with parasitic element and a compact planar 90° hybrid coupler. The asymmetric stripline based hybrid coupler serves also in impedance matching of the unit element. This integration, being at the element level, leads to realization of dual-circular polarization without the need for adopting sequential rotation techniques. Furthermore, the design does not require air substrate layers and therefore realization using conventional multi-layered printed circuit board (PCB) fabrication is possible. The simulation assisted design of the integrated unit element and the array-factor based radiation pattern for the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$16 \times 16$</tex> exhibit a realized gain greater than 25dBi and an axial ratio of around 5dB across a wide range of elevation angles.