本研究針對低軌道衛星(Low Earth Orbit Satellites)應用，設計並實現波束成形晶片，用以解決大型天線陣列在製造以及高頻段訊號傳輸過程中產生的偏差問題。低軌衛星由於軌道高度較低，天線在發射及接收信號時容易受到相位與振幅偏差的影響，進而降低訊號品質並影響天線場型。為解決此問題，本論文採用自適應波束成形技術，並採用多步長複數最小均方(Multiple Step Size Complex Least Mean Square, MSS-CLMS)演算法進行動態調整，實現對天線相位與振幅偏差的即時修正。
本設計基於1024天線的均勻間隔矩形天線陣列，透過MSS-CLMS演算法的低複雜度特性，使系統能夠在降低計算量的同時，達到快速收斂與準確的波束調整，並於天線權重中施加 Dolph-Chebyshev 權重，以使天線場型符合低軌道衛星通訊規格。最後於5G NR Beam Sweeping 的時間規範下達到修正天線相位與振幅偏差並使得天線場型符合低軌道衛星通訊規格。
為實現硬體設計，本研究採用了Cell-Based晶片設計流程，結合數位電路架構設計，將 MSS-CLMS 演算法硬體化，以實現有效的偏差修正。整體系統具備低功耗、高效能的特性，滿足實時運算需求。同時使用FPGA驗證，證明其在低軌衛星通訊中的可行性與穩定性。本設計對提升低軌衛星通訊系統的效能具備重要意義。;This research presents the design and implementation of a beamforming chip for Low Earth Orbit (LEO) satellite communication systems, aiming to correct amplitude and phase deviations in large-scale antenna arrays caused by manufacturing imperfections and high-frequency signal transmission. Due to the low orbital altitude of LEO satellites, the antenna array is particularly vulnerable to signal distortions arising from such deviations, which can significantly degrade communication quality and disrupt the radiation pattern.
To address this issue, an adaptive beamforming technique is employed, utilizing the Multiple Step Size Complex Least Mean Square (MSS-CLMS) algorithm to dynamically adjust antenna weights. This allows real-time correction of phase and amplitude errors with low computational complexity. The system is built on a 1024-element uniformly spaced rectangular antenna array, enabling scalable implementation for high-capacity satellite links. By applying Dolph-Chebyshev weighting, the antenna radiation pattern is further optimized to comply with LEO communication requirements.
The proposed beamforming architecture is designed to meet the stringent timing constraints of 5G NR beam sweeping, ensuring timely and accurate correction. A cell-based digital IC design methodology is adopted to implement the MSS-CLMS algorithm in hardware, achieving both low power consumption and high performance suitable for real-time signal processing. Functional validation through FPGA prototyping confirms the stability and feasibility of the design in LEO satellite environments.
This work provides an efficient and practical hardware solution for improving beamforming accuracy in next-generation LEO satellite communication systems, contributing to enhanced signal integrity and overall system reliability.
