宽频高隔离度双极化基地台天线阵列设计(全文)(PDF).PDFVIP

寬頻高隔離度雙極化基地台天線陣列設計 寬頻高隔離度雙極化基地台天線陣列設計 Broadband High-isolation Dual-polarized Base Station Antenna Broadband High-isolation Dual-polarized Base Station Antenna Array Design 陳偉吉 王棓熲 郭李瑞 林泰宏 Array Design Wei-Ji Chen, Joseph Poujiong Wang, Li-Ruei Kuo, Tai-Hung Lin 陳偉吉 王棓熲 郭李瑞 林泰宏 Wei-Ji Chen, Joseph Poujiong Wang, Li-Ruei Kuo, Tai-Hung Lin 中文摘要 本論文針對大型基地台天線中的雙極化共振子提出一種平面式架構，利用金屬柱連通交叉偶 極天線雙臂及反射板，改善低頻段阻抗匹配不佳之情況，進而提升共振子操作頻寬 。接著我們將 共振子初步整合成陣列並探討其表現 ，由於天線陣列本身需符合高隔離度、高前後比等規範，因 此在設定間距排列為天線陣列後，我們進一步著手改善其波束前後比與雙埠隔離度 。首先藉由反 射板塑型結構減少背向輻射場量，提升天線之波束前後比。之後於天線陣列結構加入倒L 形解耦 器與負載調整導向器來降低透過反射板耦合至鄰近共振子上之表面電流，改善天線陣列之雙埠隔 離度，在輻射體與解耦架構整合後，陣列本身仍可維持寬頻、雙極化、高輻射效率等特點。最後 我們所設計完成的實驗原型，可使得天線陣列涵蓋2600MHz~ 3800MHz 操作頻寬，雙埠隔離度達 30dB 以上，而波束前後比則可大於25dB 。 Abstract A planar broadband dual-polarized antenna element for base station applications is proposed. In order to enhance the impedance matching at lower frequency band, there are metal cylinders electrically connected to the crossed dipole arms and the reflector, respectively. In addition, we have integrated the structure into array and discussed the performance. The antenna array is required to perform high isolation and high front-to -back ratio. After arranging four antenna elements with a distance, we have tried to improve the front-to -back ratio and port-to -port isolation. First of all, by using beamforming reflector design for back lobe suppression, the front-to -back ratio can be improved. Moreover, inverted-L isolators and top-loading tunin