臺灣博碩士論文加值系統

本論文提出利用行動裝置產品的金屬外框來改善LTE(Long Term Evolution)之低頻頻寬，低頻頻段操作於690MHz～960MHz。天線型式使用單極天線，透過彎折產生出三個共振模態，並利用傳輸線耦合方式使單極天線增加頻寬。許多行動裝置會在其產品外觀使用金屬外框，金屬外框靠近天線對於天線輻射有惡化影響，本論文同樣會模擬此金屬外框的環境，放在天線外圍。

由於行動裝置產品為了美觀，會加上金屬外框來美化產品如Apple Iphone4，金屬具有導電性，能夠改變電磁波的輻射特性，若接地時會吸收電磁波能量並且行動裝置所能提供的淨空區相對較小，使得天線輻射環境又更加惡劣。

本論文提出之天線操作於三個頻段：690MHz~960MHz, 1710MHz~2170MHz, 2500MHz~2700MHz。並利用金屬外框透過接地短路與天線的接地平面連接，使金屬外框與天線產生藕合且共振，增加低頻頻寬。最後放上第二支天線，使其成為MIMO天線，更符合需求。

關鍵詞：單極天線, 耦合, 金屬外框, MIMO。

The thesis presents a novel design to lower down the minimum operating frequency and its associated bandwidth of a meandered monopole antenna. The antenna is integrated with the metal frame which is similar to that used in Apple Iphone 4. The metal frame in Apple Iphone 4 plays the role as an antenna. However, the surrounding metal frame itself is often required to provide a good looking for the mobile phone or the Table PC. It, therefore, becomes a necessary part of the product. In this thesis, we study the effect of adding a metal frame on a typical coupled meandered monopole antenna.

The monopole itself is found difficult to be operated at the low frequency of 690 MHz with enough bandwidth without adding the metal frame. However, three resonant frequency bands (690MHz~960MHz, 1710MHz~2170MHz, and 2500MHz~2700 MHz) are realizable after adding the metal frame.

Keyword: Monopole, Couple, Metal frame, MIMO

誌謝 ii
摘要 iii
ABSTRACT iv
目次 v
表次 vi
圖次 vii
第一章 序論 1
第二章 天線理論與介紹 4
第三章 天線結構與設計流程 7
第四章 MIMO結構LTE天線 23
第五章 天線量測 34
第六章 結論 53
參考文獻 54

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