方向耦合器應用於陣列天線饋入網路

Abstract

在本研究中，將使用方向耦合器(directional coupler)做陣列天線的饋入網路，並模擬此陣列天線所輻射的場形，驗證此饋入網路可有效達到柴比雪夫能量分布形式，抑制旁波瓣準位(Side Lobe Level, SLL)，降低訊雜比(Signal to Noise Ratio, SNR)。此陣列天線饋入網路適用於雷達系統上。並可以藉由本研究所提出的各階耦合器的耦合係數計算方式，與整理出的方向耦合器特性查找表，簡化複雜的設計流程，比起傳統的T型接面(T-junction)饋入網路來的容易設計，降低了不連續性造成的影響。在本文會附上饋入網路接上天線的輻射場型，驗證此饋入網路能有良好的高增益、低旁波瓣準位的特性。

In this thesis, directional couplers are used as the feeding network of the array antenna. The radiation pattern of this antenna array is simulated to verify that the feeding network can effectively reach the Chebyshev distribution. This feeding network can suppressed the side lobe level (SLL) and reduced the signal to noise ratio (SNR). This array antenna feed network is suitable for use in radar systems. It can simplify the complicated design flow by using the directional coupler characteristic look-up table. Compared with the traditional T-junction feeding network, it is easier to design. Finally, we attach the radiation pattern of the array antenna, verify that can have a high gain,characteristics of low side lobe level.