Compact Broadband Monopole Antenna for Digital Television Application

由於電視廣播的數位化，可充分提升電視播放影像和聲音的品質，增加多媒體的加值服務，利於通信與電子產品的整合，開發更多元化的商機，所以建立數位電視整體環境已成趨勢。本研究針對數位電視播放的地面廣播傳輸方式，提出一種小型且平面化的數位電視接收天線設計，將天線製作於印刷電路板上，達到製作容易及降低成本的控制，並且方便內嵌於可攜式產品中，例如：筆記型電腦或數位電視盒等電子產品，達到節省空間及美觀的功能。本研究採用單極天線作為設計基礎，由帶有矩形狹縫的貼片金屬及微帶線作饋入所組成，再搭配凹槽式的接地面以及位於貼片金屬背部的一塊中空金屬平面來達到阻抗匹配，完成數位電視的頻寬需求，且涵蓋DVB-T系統的操作頻段(470~862MHz)。在輻射場型的分佈上，因為是利用單極天線的設計概念，所以會有類似甜甜圈形狀的3D輻射場型，在接收訊號上較無死角。詳細的天線設計分析與量測結果會在論文中說明。Digital television (DTV) is an advanced technology that enables television stations to provide better pictures and sound quality. It can also offer multimedia service and great interactive capabilities. The date when television goes all digital has changed. In this thesis, we propose a compact planar monopole antenna for DTV applications on the terrestrial television broadcasting. The proposed antenna can be printed on dielectric substrate by using printed circuit board technique. Also, the proposed antenna has good feature owing to its low cost in fabrication and ease of construction. It can be easily placed into a portable device such as notebook or TV box. The proposed monopole antenna which consists of microstrip line and a patch with rectangular slits. The wideband property is achieved by using a ground plane with notch and a slotted plane on the monopole back side. These techniques are used to enhance the impedance-matching of the proposed antenna. The proposed antenna canrovide a wide operating bandwidth for DVB-T signal reception in the UHF band. The measured radiation patterns show the good characteristics in the operating frequency bands. Details of the proposed antenna designs, analysis, and experimental results of the constructed prototypes are also included.口試委員審定書 i謝 ii文摘要 iiibstract iv一章 緒論 1.1 研究動機與目的 1.2 章節概述 2二章 天線設計之基本原理與相關文獻 32.1 偶極天線原理 32.2 文獻回顧 7三章 數位電視接收天線的設計背景 113.1 電視天線的分類與說明 113.2 天線設計需求與考量 12四章 小型化數位電視接收天線設計 144.1 前言 144.2 設計構想 144.3 天線架構 194.4 天線設計細部說明與參數分析 224.5 天線輻射特性 334.6 天線設計流程 404.7 產業實用性和可商業化程度的考量 41五章 結論 44考文獻 45錄A 數位電視基本簡介 47A.1 何謂數位電視 47A.2 數位電視應用的優點 47A.3 數位電視傳輸標準 5