A 256-Element Ku-Band Polarization Agile SATCOM Receive Phased Array With Wide-Angle Scanning and High Polarization Purity

Abstract

This article presents a Ku-band phased-array receive tile with 256 elements. The design is based on 64 dual-polarized beamformer chips assembled on a printed circuit board (PCB) with dual-polarized antennas and an integrated Wilkinson combiner network and can operate at any polarization (linear, rotated-linear, and circular). The 256 elements are spaced <inline-formula> <tex-math notation= LaTeX >$0.52\\lambda $ </tex-math></inline-formula> apart at 12.7 GHz in the <inline-formula> <tex-math notation= LaTeX >$x$ </tex-math></inline-formula>- and <inline-formula> <tex-math notation= LaTeX >$y$ </tex-math></inline-formula>-directions. The measured patterns show near ideal patterns with a wide beam scanning range of ±70° (V- and H-pol) and a high cross-polarization rejection of 27 dB. The array has a 3-dB instantaneous scanning bandwidth of 10.6–12.5 GHz. In circular polarization mode, the measured axial ratio (AR) is 0.5 dB at 11.75 GHz for both left- and right-hand circular polarizations. The tile design is scalable to allow large-scale phased-array construction with 1024 elements or higher. Extensive measurements are presented, showing the versatility of this approach. Also, the dual-polarization feeds can be optimized to result in very low cross-polarization for circular and slanted-linear polarizations at all scan angles. The array performance, compact size, ultralightweight of 258 g, and low profile with 3.5-mm thickness make it suitable for affordable mobile Ku-band SATCOM on the move (SOTM) terminals.