在電子戰的情境中，軍事載具上的電子反制設備必須要對電波源達到高靈敏度與高測向精度的效能，始能有效對抗先進的雷達裝備。而相位干涉儀演算法因為計算量低、原理簡單等緣故，常被運用於測向技術上，其藉由相鄰天線接收到的相位差，且利用不同的間距擺放方式配上演算法，估算訊號源入射來向。在一維相位干涉儀非均勻線性天線陣列系統中，若增加基線長度，可以增加估測訊號來向角的精準度，而混淆機率也會隨之上升，此時我們須在兩者之間抉擇如何得到最佳的權衡，意即最低的方均根誤差(RMSE)。我們利用數學推導的方式，整理出在不同情況下，三波道干涉儀演算法的RMSE通式，藉由此RMSE數學式，可以模擬在AWGN通道中當最大長度固定情形下，RMSE最低的其天線間最佳間距比為何者。
此外我們整理出三個不同的演算法，依照其演算法最終判定角度的條件不同，比較其效能差異，並推導其RMSE通式，也對照使用RMSE通式與使用演算法模擬的效能，兩種結果是否一致，最後透過此RMSE通式，提出RMSE最小化的最佳間距比。

In the context of electronic warfare, electronic counter-devices on military vehicles must achieve high sensitivity and high direction-finding accuracy for radio waves, and can effectively combat advanced radar equipment. Because of its low computational complexity and simple principle, the phase interferometer algorithm is often used in direction finding technology. Direction of the signal is estimated by the phase difference received between two antennas and uses interferometer algorithm to solve ambiguity. In the one-dimensional phase interferometer nonlinear antenna array system, If the baseline is lengthened, the accuracy of the angle of the estimated signal can be more accurate, but the probability of ambiguity will also increase. At this time, we have to choose the best trade-off to get lowest root mean square error (RMSE). We use mathematical derivation to propose an RMSE formula for algorithms. By using the RMSE formula, we can simulate and choose the optimal array ratio between the receivers in the AWGN channel.
In addition, we choose three different algorithms according to the difference in the value of the angle of the direction. By deriving its RMSE formula and comparing its performance, we can use this RMSE formula to compare the advantages and disadvantages. Finally, the optimal array ratio of RMSE minimization is proposed by this RMSE formula.

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