A Ku-Band Dual-Polarized 1024-Element Receive Phased-Array with Four Simultaneous Beams

This paper presents a 1024-element Ku-band dual-polarized receive phased-array at 14-15.6 GHz with simultaneous four-beam capabilities. The array is built on a multi-layer printed circuit board (PCB) with 512 16-channel commercial beamformer chips in SiGe which results in a total of 8096 receive beamformer channels, each with independent gain and phase control. For each dual-polarized antenna, a 2-channel low noise amplifier (LNA) is used to improve the system noise figure (NF). The 1024-element phased-array has a measured antenna gain-to-noise temperature $(\mathrm{G}/\mathrm{T})$ of $7.5\ \text{dB}/\mathrm{K}$ at broadside $(\mathrm{T}_{\text{ant}}=295\mathrm{K})$ for each beam. Every beam of the phased-array has a scanning range of $+/-60^{\circ}$ in azimuth plane and $+/-45^{\circ}$ in elevation plane with low sidelobes, and a $< -20 \ \text{dB}$ cross polarization levels at all scan angles is achieved. The phased array is polarization agile and can be configured into linear, right-hand circular and left-hand circular polarization. Thanks to its four-beam capability, the array is capable of supporting four concurrent data streams with different directions of arrival and a $> -40 \ \text{dB}$ beam-to-beam isolation is obtained. To the authors' knowledge, this is the first demonstration of large-scale receive phased array with four simultaneous beams on the same aperture at this frequency band and is a good candidate for Ku-band communication links.

I. Introduction

Recently, planar active electronically scanned array (AESA) based on silicon chips have been developed at a very fast pace. The cost of phased array deployment has been reduced by a large extent due to the advancement in silicon technology and multi-layer PCB manufacturing. This is especially true in the satellite industry, where companies such as Starlink, OneWeb and Amazon Kuiper have invested billions of dollars to establish their LEO constellations to provide internet service to users.