線性及圓形極化廣角回波陣列天線

LINEAR AND CIRCULAR POLARIZATION VAN ATTA ARRAY ANTENNA

吳睿軒(Jui-Shuan Wu)

指導教授 ： 張知難

大同大學/電機資訊學院/通訊工程研究所/碩士(2007年)

摘要

在本篇論文中，提出一種被動式的廣角回波反射陣列天線，以4個環形天線為單元，每個單元利用兩條傳輸線偶合來激發，饋入在互相垂直的位置上。兩個天線單元間對稱於中心並採用整倍數波長的連線(Van Atta Principle)，因此能達到二維回波的特性。我們藉由IE3D的模擬和實驗來驗證，這種架構下有能力同時滿足對線性及圓形極化的回波。在論文中對於圓形極化的回波也做了進一步的討論。
在本文中所提出的架構下不論是圓形還是線性極化，藉由成對的天線單元所回傳的波，由於和直接從天線散射回來的干擾在不同的極化方向上，因此可以得到較為平坦的回波場型。在頻率為5GHz線性極化時，量測到的10-dB的波束寬為140°，而在10GHz圓形極化時，量測到的波束寬為130°, 它們都比從相同大小的金屬板反射的波束還要寬許多。

關鍵字

廣角回波陣列天線 ； 線性極化 ； 圓形極化

並列摘要

A simple passive microstrip array design is introduced comprising four ring antenna elements, and each element was excited by stripline-coupled fed from two orthogonal feeding ports. The striplines is arranged to form a Van-Atta retrodirective array which has two-dimensional self-tracking ability. We validate that this structure is catered for both linear and circular polarizations by simulation with IE3D and experiment. The fields retransmitted by all the antenna pairs spatially combine in the wave-incidence direction while interfere with each other in other directions, so that the reradiated field is smooth. The measured 10 dB responding beamwidth at 5GHz for linear polarization is 140°, and the measured 10dB responding beamwidth at 10GHz for circular polarization is 130°, both of them are much wider than the beamwidth of reflection from metal sheet with the same size.

並列關鍵字

retrodirective array antenna ； linear polarization ； circular polarization

參考文獻

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