K-/Ka-band Shared-aperture Dual-CP Phased Array Based on Amplitude-regulated Sequential Feeding for Satellite Communication

SSatellite communication (SATCOM) is essential for 6G networks, supporting Space-air-ground Integrated Network (SAGIN) and global coverage especially in remote and mobile scenarios. This work proposes a novel dual-band dual-circularly polarized (CP) shared-aperture phased array using amplitude-regulated sequential feeding (ARSF) for simultaneous K-band (downlink) and Ka-band (uplink) CP operation in SATCOM. Theoretical analysis demonstrate amplitude regulation between multiple linearly polarized (LP) components enables effective CP synthesis despite significant phase gradient φ deviates from 90°, allowing for broader CP bandwidth (over 100%) or dual-band CP operation without complex phase-shift networks. The dual-band (K-/Ka-band) and higher-band (Ka-band) elements employ metasurface (MS) as radiator with identical lamination stack-up. Subsequently, the proposed K-/Ka-band shared-aperture array is constructed by 4 × 4 dual-band elements and 8 higher-band elements to ensure dual-band wide-angle scanning capacity. Both simulated and measured results confirm the dual-band operation. The array achieves scanning angles up to ±55° in K-band and ±60° in Ka-band, with axial ratio (AR) and gain drops ≤ 5 dB. Practical implementations could necessarily scale the array to achieve uniform scanning angle (e. g., ±60°) across bands while preserving transmit/receive (Tx/Rx) frequency division duplexing. This compact, lightweight, low-cost array offers high integration and wide-angle scanning capabilities, which is ideal for 6G unmanned aerial vehicles (UAV) applications.