Wide Axial-Ratio Bandwidth and Scanning in Dual-Beam Phased Array for SATCOM Receiver

The large-scale deployment of low-Earth orbit (LEO) satellites opens significant commercial opportunities for developing low-cost satellite communication (SATCOM) user terminals. To meet the growing demand for dynamic tracking of fast-moving LEO targets, we present a dual-beam, independently controlled <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">K</i> band (17.7–21.2 GHz) SATCOM phased-array receiver. This system integrates a dual-beam architecture, a new dual-circular-polarization (CP) antenna, a passive power combiner network, and a dual-beam digital control system. The designed antenna element, formed by a dual-layer asymmetric metasurface patch embedded in metal vias, achieves excellent impedance matching for large-angle incoming waves, enabling the configured array to achieve wide-angle scanning of ±70° following <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\cos \theta $</tex-math> </inline-formula> roll-offs and superior axial-ratio (AR) bandwidth under extreme scanning conditions. Experimental measurements confirm its outstanding performance, including low-sidelobe levels (SLLs), high-cross-polarization discrimination (XPD), a wide 3-dB AR bandwidth, and a wide-angle (>60°) AR scanning across the spectrum. The receiver supports independent dual-beam operation at arbitrary frequencies, polarizations, and scan angles and enables an excellent gain-to-noise temperature (G/T) of 9.45 dB/K, a high signal-to-noise ratio (SNR), and a proven communication link with a high data rate (the actual throughput reaches 60 Mb/s), marking a leap forward for commercial SATCOM systems.