印刷式寬頻數位電視天線

Abstract

數位廣播系統是一種比現在的類比廣播系統更能傳送較多的頻道以及較佳的影像、聲音品質的新技術。數位電視將會愈來愈流行而類比訊號的電視將會被逐漸淘汰。 本論文中，我們將研究適用時DVB廣播系統(470MHz~862MHz)的可攜的印刷式寬頻天線且它們滿足對DVB天線的增益規範。 我們選擇了折繞式金屬線作為天線的饋入結構以減小面積，使用梳形架構 改善阻抗頻寬，然後放置了一些寄生元件來提高輻射效率。並且使用了一種梯形架構作為寬頻負載來進一步得減小面積。 本論文中是使用Ansoft公司所出版的HFSS模擬軟體來模擬與設計各種天線架構。而由於量測儀器上的限制，本論文中在800MHz以下的輻射場型只有模擬的結果。

The Digital broadcasting system is a new method of transmitting television signals that gives access to more channels, better quality of image and sound over the current analogue broadcasting system. The digital TV will be more popular and the analogue TV will be phased out soon. In this thesis,we study portable printed broadband antennas which are suitable for DVB broadcasting system(470MHz~862MHz) and meet the specification of the antenna gain for DVB broadcasting system. We choose the meandered line as the feeding structure of the antennas to reduce the size, use the comb structure to improve the impedance bandwidth, and then put some parasitic elements to enhance the radiation efficiency. We also use trapeziform structure as the broadband loading to reduce the size further. In this thesis,Ansoft HFSS is used to simulate and design every kind of antenna structure. Because of the restrictions of the measurement equipments,we only present the simulated pattern below 800MHz in this thesis.