新型態多天線系統綜合分析

Abstract

在本論文中，我們提出了兩組新型評估多天線系統效能的電磁分析。第一項是新型天線空間相關係數(Antenna Spatial Correlation)的計算方法，第二項則是結合全主動反射係數(Total Active Reflection Coefficient)的輻射效率(Radiation Efficiency)分析方法。論文中的所有個案討論將以一對偶極天線做為分析基準。 首先，我們提出了一組新型態的天線空間相關係數表式方法。新型天線空間相關係數計算方式擁有以下的優勢。首先，新型態的計算方法將整體的計算參數化，分離了天線場型、天線電路的耦合效應(Mutual Coupling Effect)以及入射角度的機率分佈函數(Angle-of-Arrival Probability Distribution Function)三組參數進行計算，如此的計算方式可以將三者分別對相關係數的影響進行檢驗，有利於對於整體效能的分析評估，並可節省計算受到耦合效應影響的天線場型的時間。再者，在進行關於入射角度的機率分佈的相關計算中，我們提出了計算任意入射角度分佈的相關係數積分近似方法，此方法可以有效降低計算複雜度。 此外，我們也提出了一組新的結合全主動反射係數的輻射效率分析方式。他能分析輻射效率如何隨著天線埠饋入不同相位訊號時有所改變，相對也更適合於多天線系統的分析。運用這一組分析方法，我們也進一步研究不同的天線匹配網路如何影響輻射效率以及天線空間相關係數。

In the thesis, we propose two new electromagnetic analysis strategies to evaluate the performance of multiple antenna systems. The first is a new antenna spatial correlation formulation, and the other is a new analysis strategy of radiation efficiency combined with total active reflection coefficient (TARC). All case studies are simulated using a dipole pair as the benchmark. The new proposed antenna spatial correlation formulation is presented in the parameterized manner. The formulation separates the isolated antenna pattern, the mutual coupling effect between antennas, and the probability distribution function (PDF) of Angle-of-Arrival (AoA) to calculate the correlation coefficient. Such formulation not only benefits the analysis of the performance of the whole antenna system but also saves the computation time of the distorted antenna patterns which result from the mutual coupling effect. Moreover, we provide an approximate spatial correlation formulation which is suitable for arbitrary AoA scenarios and can be incorporated in our parameterized correlation formulation. This approximation formulation can effectively reduce computation complexity. We further propose a new analysis strategy of radiation efficiency combined with TARC technique. It evaluates how the radiation efficiency may change when the antenna ports excite signals with different phases. Besides, with this new technique, we also investigate how different antenna termination networks influence the radiation efficiency and antenna spatial correlation.