A planar Ka-band phased array with configurable polarizations

In this paper, a Ka-band polarization agile antenna array is demonstrated. Two linearly polarized sub-arrays, the series-fed patch sub-array and the substrate integrated waveguide (SIW) slot sub-array, are used together to form a RHCP, LHCP or dual-LP phased array. The patch array and slot array have similar aperture dimensions with inherent orthogonal E-field orientations. Such arrangement eliminates physical rotation of the LP elements and maintains excellent CP axial ratio for the entire beam. The switch between the four possible polarizations is simply done by the same phase shifters used for beam steering. This array is designed on single layer PCB manufacturing which is ideal for low cost millimeter wave beam scanning and MIMO systems requiring polarization diversities.