本論文提出考慮並補償天線陣列互耦合效應(mutual coupling effect)之寬頻信號來向角(direction of arrival, DOA)估測方法。向量子空間(subspace)方法是一種利用天線陣列接收信號估測來向角的高解析度方法，且適用於多入射信號的情境。然而向量子空間方法通常基於理想天線陣列進行探討，並假設已知入射信號數目。但在實際應用時天線彼此之間將存在互耦合效應，不同頻段及天線間距也會有不同的互耦合效應。此效應將影響天線陣列接收信號的大小及相位，並導致來向角估測方法的效能下降。
本論文結合信號數目偵測方法、互耦合補償(mutual coupling compensation)與寬頻向量子空間方法對寬頻信號進行來向角估測。天線陣列接收的寬頻信號將會被分解為多個窄頻分量，並先行用於偵測入射信號數目。偵測之入射信號數目將用於寬頻向量子空間方法，在對各個窄頻分量進行對應頻率之互耦合補償的同時，進行寬頻信號來向角估測。
本論文使用電磁模擬軟體HFSS進行偶極天線之均勻矩形陣列的互耦合效應模擬，利用演算法模擬軟體MATLAB進行本論文提出方法的功能驗證與效能分析，並且探討不同互耦合補償方法對於信號數目偵測與信號來向角估測的影響。模擬結果顯示若先不對天線陣列接收信號進行互耦合補償，直接偵測信號數目，反而可以避免嚴重錯誤；而藉由對各個窄頻分量進行對應頻率的互耦合補償，則能夠有效降低寬頻信號的來向角估測誤差並提升角度解析度。

This thesis addresses the direction of arrival (DOA) estimation for wideband signals in presence of mutual coupling. Subspace-based DOA estimation studies are high resolution methods and suitable for multiple impinging signals. However, these methods generally utilize ideal antenna array without considering the effect of mutual coupling, and assume the number of signals to be the given information. The mutual coupling effect varies with the frequencies of signals and interspace of antennas. This effect would affect the magnitude and phase of received signals and consequently degrade the performance of the DOA estimation algorithm.
This work proposes a method of wideband signal DOA estimation based on signal number detection, mutual coupling compensation (MCC) and wideband subspace method. The proposed method decomposes received wideband signals into a set of narrowband components before detecting the number of signals. The DOA estimation for wideband signals is then applied using compensated narrowband components and the detected number.
In this work, the effect of mutual coupling of an antenna array is simulated by the electromagnetic simulation software, HFSS, and the proposed DOA estimation method is verified through computer simulations. The result of different MCC methods on signal number detection and DOA estimation is also studied. The simulation results indicate that the signal number detection could instead avoid the detection error without MCC, and the proposed method with MCC improves the performance of DOA estimation for wideband signals as well as the angle resolution.

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