超寬頻(Ultra-Wideband, UWB) 技術，最早起源於西元1970年代，應用於軍方國防部門雷達通訊系統。隨著近年來無線通訊的傳輸需求從聲音、數據、影像到現今的多媒體應用，無線傳輸速度需求日益增大。隨著西元2002年2月14日美國聯邦通信委員會FCC（Federal Communication Commission）開放原先軍方國防部門所使用超寬頻技術，超寬頻通訊技術開始使用於消費性(Consumer)電子產品上。
無線超寬系統的主要關鍵技術之一在設計一輕巧(Compact)、寬頻且全向性的天線，本研究針對全平面式的結構，採用厚0.4mm的FR4基板，以相對介電係數(Relative Permittivity)為4.4，Dielectric Loss Tangent為0.02，來進行模擬並和實驗相驗證，設計一符合3GHz ~ 5GHz UWB頻帶全平面式微帶單極天線，並進一步將此一全平面式天線縮小化與結構簡單化，使其降低生產成本與更易實際製作於印刷電路整合。
在全平面式超寬頻單極天線結構的縮小化設計及增加天線頻寬上提出兩種新的設計技巧：其一是以天線初始結構，設計底部半圓形單極輻射體(Semi-Circular Base)並且加上對稱縫隙(Slit) 的形狀以達到天線縮小化目的，進而發現除了控制天線接地面(Ground Plane)和單極輻射體(Radiator)間隙，可改變天線虛部阻抗電容與電感性外，以單極輻射體增加縫隙(Slit)方式，可在不增加天線整體尺寸前提下，亦可調整天線虛部阻抗電容與電感性；其二則設計一接地面對稱寄生(Parasitic)架構，使天線同時達成寬頻匹配及縮小化的目的。經模擬與實測驗證，天線面積可縮小達33％。
為了考慮到實際製作與與降低生產成本，除本研究天線結構為全平面結構外，另提出一天線簡化結構，其寬頻匹配特性仍維持3GHz ~ 5GHz UWB頻段。得到簡化結構後，本研究進一步藉由天線接地長度的縮短，探討天線尺寸的縮小極限，雖然天線匹配隨著接地面長度縮短而劣化，但若搭配應用本研究所提出之增加縫隙(Slit)結構方法，可改善其接地面長度縮短的劣化影響，進而達到寬頻匹配特性。
考慮到H-plane上的場型維持全方向(Omni-Directional)輻射場型特性，本論文所提出增加縫隙(Slit)與寄生(Parasitic) 架構均為對稱性結構，其實測結果顯示其H-plane上的全方向(Omni-Directional)輻射場型特性確實非常良好。

Ultra-wideband technology brings the convenience and mobility of wireless communications to high-speed interconnects in devices throughout the digital home and office. Designed for low-power, short-range, wireless personal area networks (WPANs), UWB is the leading technology for freeing people from wires, enabling wireless connection of multiple devices for transmission of video, audio and other high-bandwidth data. 
Nowadays, one of major key technology of UWB system is to design a compact, wideband and omni-directional antenna. During these ten years, planer monopole antennas are used as wide band antennas. However, two-dimensional 3GHz~5GHz UWB antennas are seldom investigated in the literatures. In this research, we propose a whole planer 3GHz~5GHz UWB antenna and employ both slit and parasitic methods to increase the bandwidth of the antenna with miniature characteristic.
Two techniques are proposed to miniature compact design of the planar UWB monopole antennas and increase antenna bandwidth. One technique is to design the slit shape on the monopole radiator to miniature antenna. Antenna reactance can be changed by this slit shape structure instead of increasing the gap size between monopole radiator and ground plane which increases the antenna dimensions. By these two techniques, the antenna size can be reduced about 33％.
To reduce manufacture cost and practical fabrication, we also propose a simplified antenna structure. Wideband characteristics of the simplified structure antenna are similar to that of semi-circular structure. Moreover, we also try to find the minimum size of the antenna. Wide band characteristics are defect when the dimension of the antenna is further reduced by decreasing ground length. However, slit structure method is employed to improve antenna wideband characteristic.
Finally the antenna prototypes are fabricated and the antenna characteristics are measured. The antenna characteristics measured includes the S parameter and radiation patterns. The consistency between the simulated results and the measurement results confirm the practicability of these techniques.

中文摘要‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧Ⅰ
英文摘要‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧Ⅱ
第一章 概論‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧01
1.1 研究背景‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧01
1.2 研究動機‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧07
1.3 研究方法‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧11
1.4 論文架構‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧12
第二章 平面寬頻單極天線之設計原理‧‧‧‧‧‧‧‧‧‧‧‧13
2.1 設計原理分析‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧13
2.2 傳統寬頻天線的演化‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧19
2.3 單極天線初始結構的計算‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧21
2.4 天線接地面和單極輻射體的結構參數原理分析‧‧‧‧‧‧‧26
第三章 天線設計與量測‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧30
3.1 單極輻射體增加縫隙(Slit)結構設計‧‧‧‧‧‧‧‧‧‧‧30
3.2 單極天線接地面寄生結構設計‧‧‧‧‧‧‧‧‧‧‧‧‧‧33
3.2.1 簡化單極天線結構‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧37
3.2.2 單極天線接地面縮小化‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧39
3.3 天線輻射場型之模擬與量測‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧42
3.4 天線之整體尺寸比較‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧49
第四章 結論‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧51
參考文獻‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧‧53
圖目錄
圖1.1：UWB信號發射強度示意圖•••••••••••••••01
圖1.2：超寬頻通訊與其它通訊系統發射功率比較圖••••••03
圖1.3：MB-OFDM頻帶分配示意圖••••••••••••••05
圖1.4：立體式雙圓錐形偶極天線演化至平面式三角形單極天線示意圖••••••••••••••••••••••••••••09
圖2.1：無窮長偶極圓錐形天線結構示意圖••••••••••17
圖2.2：無窮長偶極圓錐形天線電壓與電流示意圖•••••••18
圖2.3：無窮長偶極圓錐形天線等效傳輸線示意圖•••••••18
圖2.4：寬頻單極天線演進圖(a) 傳統細線單極天線；(b) 立體單極   圓錐形天線；(c) 平面單極錐形天線；(d)半球形單極天線••••••••••••••••••••••••••••19
圖2.5：圓柱型單極天線示意圖•••••••••••••••22
圖2.6：方形單極天線示意圖••••••••••••••••22
圖2.7：圓形單極天線示意圖••••••••••••••••23
圖2.8：底部半圓形單極天線示意圖•••••••••••••24
圖2.9：底部半圓形單極天線初始結構示意圖•••••••••26
圖2.10：接地面間隙高度g變動對 參數之影響•••••••••27
圖2.11：接地面間隙高度g變動對天線輸入阻抗之影響•••••27
圖2.12：底部半圓形單極天線等效電路模型••••••••••29
圖3.1：底部半圓形單極天線加上縫隙(Slit)結構示意圖••••31
圖3.2：縫隙長度(S)變動對 參數之影響•••••••••••32
圖3.3：縫隙長度(S)變動對天線輸入阻抗之影響••••••••33
圖3.4：底部半圓形單極天線加上接地寄生結構示意圖•••••34
圖3.5：接地面寄生長度(P)變動對 參數之影響••••••••35
圖3.6：接地面寄生長度(P)變動對天線輸入阻抗之影響•••••35
圖3.7：天線結構參數：L=10、L =24、W =11、g=1、S=6.7、P=3模擬與實作 比較圖••••••••••••••••••••••36
圖3.8：底部半圓型天線實作圖•••••••••••••••36
圖3.9：單極天線簡化為方形結構示意圖•••••••••••37
圖3.10：簡化天線結構參數：L=10、L =24、W =11、g=1、S=6.7、P=3模擬與實作 比較圖•••••••••••••••••••38
圖3.11：簡化結構方形天線實作圖••••••••••••••38
圖3.12：接地面長度(L )變動對 參數之影響•••••••••39
圖3.13：接地面長度(L )變動對天線輸入阻抗之影響••••••40
圖3.14：接地面長度L =21時縫隙(Slit) S長度變動對 參數之     影響••••••••••••••••••••••••••41
圖3.15：接地面長度L =21時縫隙(Slit) S長度變動對天線輸入阻抗之影響•••••••••••••••••••••••••42
圖3.16：方形簡化結構天線E-plane(X-Z平面)輻射場型模擬結果(@3GHz)•••••••••••••••••••••••••43
圖3.17：方形簡化結構天線E-plane(X-Z平面)輻射場型模擬結果(@4GHz) •••••••••••••••••••••••••43
圖3.18：方形簡化結構天線E-plane(X-Z平面)輻射場型模擬結果(@5GHz)•••••••••••••••••••••••••44
圖3.19：方形簡化結構天線H-plane(Y-Z平面)輻射場型模擬結果(@3GHz)•••••••••••••••••••••••••44
圖3.20：方形簡化結構天線H-plane(Y-Z平面)輻射場型模擬結果(@4GHz)•••••••••••••••••••••••••45
圖3.21：方形簡化結構天線H-plane(Y-Z平面)輻射場型模擬結果(@5GHz)•••••••••••••••••••••••••45
圖3.22：方形簡化結構天線E-plane(X-Z平面)輻射場型實測結果(@3GHz)•••••••••••••••••••••••••46
圖3.23：方形簡化結構天線E-plane(X-Z平面)輻射場型實測結果(@4GHz)•••••••••••••••••••••••••46
圖3.24：方形簡化結構天線E-plane(X-Z平面)輻射場型實測結果(@5GHz)•••••••••••••••••••••••••47
圖3.25：方形簡化結構天線H-plane(Y-Z平面)輻射場型實測結果(@3GHz)•••••••••••••••••••••••••47
圖3.26：方形簡化結構天線H-plane(Y-Z平面)輻射場型實測結果(@4GHz)•••••••••••••••••••••••••48
圖3.27：方形簡化結構天線H-plane(Y-Z平面)輻射場型實測結果(@5GHz)•••••••••••••••••••••••••48
圖3.28 ：天線H-plane實測之輻射增益值的比較圖•••••••49
表目錄
表1.1：MB-OFDM頻帶分配表Band Group Allocation••••••06
表3.1：天線整體尺寸比較表••••••••••••••••50

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