臺灣博碩士論文加值系統

本研究開發了一分集天線量測系統並提出可包含LTE全頻帶的寬頻天線設計。第一部分提出了一個低成本、半自動的量測系統架構，可用來對多天線系統的有效分集增益做評估。架構分成發射端及接收端兩個部分。發射端由訊號產生器及參考天線提供一連續波訊號；接收端包含一個控制用的主機、多通道資料擷取卡、RF功率檢測器，以及待測的多天線系統。系統可自動讀取並記錄數據，在一富含多重路徑且無嚴重背景雜訊的環境中，可以快速獲得多天線系統的有效分集增益值。為了驗證量測系統的有效性，本研究對分集天線以及多天線系統進行了測試。相較於現有的分集效能評估方法，此量測系統不僅提供了合理的量測結果，更節省了大量的時間和人力。此外，它可以同時量測大量的天線，滿足高階MIMO多天線系統的評估需要。
第二部分提出了一個在平板上使用，支援MIMO的LTE雙天線系統架構。為了能在窄邊框的行動裝置中使用，天線使用軟性印刷電路板製成。天線結構簡單，主要由摺疊的金屬片及槽縫所構成。該設計可以提供非常大的操作頻寬，常用的LTE頻段，包括690至960 MHz和1710至2690 MHz都可涵蓋在內，並擁有不錯的匹配和輻射特性。本研究也將此天線設計成一個雙天線系統的架構，透過改變兩個天線在平板上的擺放位置，取得一個合理的隔離度表現，並透過破地結構技術進一步降低天線間的耦合。輻射場型和封包相關係數都顯示其具有良好的分集效能。在多重路徑豐富的環境中，進行測量並取得有效分集增益值。結果證明，此雙天線系統可符合MIMO系統的傳輸需求。

This thesis is focused on the development of an antenna measurement system and a broadband antenna applicable for LTE uses. The first part is about a low-cost, semi-automatic effective diversity gain measurement system for multi-antenna systems. It comprises a transmitter and a receiving end. Continuous waves are provided by a signal generator and emitted from a reference antenna. The receiving end contains a control computer, a multi-channel data acquisition card, RF power detectors, and the multi-antenna system under test. The system can automatically read and record the data. Measurements of basic diversity antenna setups as well as multi-antenna systems were tested to validate the effectiveness of the proposed approach. Comparing to existing diversity evaluation methods, this approach provides not only convincing results but also saves a lot in time and cost.
The second part is about a two-antenna system for LTE MIMO uses on tablets. To be integrated within slim portable devices, the proposed antenna is made with a flexible printed circuit board. The antenna structure is simple, which is a folded metal sheet with slots. It provides very broad operation bands. Commonly used LTE bands including 690 to 960 MHz and 1710 to 2690 MHz bands are covered with decent matching and radiation characteristics. A two-antenna displacement scheme on tablet is proposed with a fair isolation performance. The defected ground structure technique is employed to further reduce antenna coupling. Performance features such as radiation patterns, envelope correlation coefficient and effective diversity gain are measured. All the results validate that it is suitable for MIMO uses.

摘要 I
ABSTRACT II
誌謝 III
目錄 V
圖目錄 VII
表目錄 IX
第一章 緒論 1
1.1. 研究背景與動機 1
1.2. 論文組織 2
第二章 多天線有效分集增益量測系統 3
2.1. 前言 3
2.2. 天線分集原理與瑞雷分布 7
2.2.1 天線分集方式 7
2.2.2 瑞雷分布 8
2.3. 量測系統 10
2.3.1 系統架構 10
2.3.2 程式&程式介面 11
2.3.3 量測方法 12
2.4. 天線量測系統之效能驗證 17
2.4.1 基本天線架構 17
2.4.2 多天線系統架構 22
2.5. 天線量測系統之限制 29
2.6. 小結 34
第三章 應用於手持裝置及平板之全頻段軟板LTE天線設計 35
3.1. 前言 35
3.2. 天線設計與參數分析 38
3.2.1 天線結構 38
3.2.2 共振模態分析 40
3.2.3 天線參數分析 44
3.3. 在平板上之雙天線設計與參數分析 47
3.3.1 雙天線在平板上之擺放位置 47
3.3.2 雙天線解耦合結構 51
3.4. 天線之效能驗證 52
3.4.1 單天線效能驗證 52
3.4.2 雙天線系統效能驗證 58
3.5. 小結 62
第四章 結論 63
參考文獻 65
附錄I 71
附錄II 75
附錄III 76

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