C/X/K/Ka Multibeam Phased-Array Receiver Terminals for Maritime LEO SATCOM

The maritime satellite communications (SATCOM) plays an important role in the space-air-ground-sea communications. This paper presents $\mathbf{C} / \mathrm{X} / \mathrm{K} / \mathrm{Ka}$ phased array receiver terminals for maritime SATCOM, which are characterized by the reconfigurable multibeam that supports flexibly simultaneous multi-user data transmission. The development of the terminals has overcome significant challenges spanning from chip design and array assembly to beam alignment algorithms. The low-profile integrated multibeam phased array receiver terminals are developed based on the self-produced multibeam integrated circuits (ICs), which boast state-of-the-art phase and gain control performance. To calibrate amplitude-phase error, a calibration algorithm utilizing deep residual neural networks is proposed and implemented. To overcome the challenge arising from the coupled motion between the phased-array terminals and satellites under the maritime LEO SATCOM scenario, a beam alignment algorithm based on multi-channel phase weighting (MCPW) is proposed for the unique structure of multi-beam analog phased arrays. Both simulation and measurement results validate the performance of the multibeam phased array terminals.

I. Introduction

Satellite communication (SATCOM) network emerges as the primary solution for achieving ubiquitous and oceanic communications. Contrasted with conventional geostationary orbit (GEO) SATCOM systems, the latest generation of low earth orbit (LEO) SATCOM systems boasts superior attributes including enhanced throughput, reduced latency and cost. The phased array terminals with reconfigurable multibeam provides potential superiority in the LEO SATCOM. Given the fleeting duration of a LEO satellite covering a terminal, the utilization of multibeam terminals allows for concurrent beam switching by enabling some beams for searching subsequent LEO satellites without terminating the ongoing communications based on the remaining beams. Considering the fact that in a large scale LEO satellite constellation a terminal is able to reach multiple satellites at a time, the terminals employing multibeam technology facilitates concurrent multiuser communication. We therefore believe that the development of a multibeam phased array terminal for LEO SATCOM is of great significance.