供DVB-H與WLAN應用之寬頻微帶天線之設計

DESIGN OF WIDEBAND MICROSTRIP ANTENNAS FOR DVB-H AND WLAN APPLICATIONS

陳威佑(Wei-Yu Chen)

指導教授 ： 黃啟芳

大同大學/電機資訊學院/通訊工程研究所/碩士(2008年)

摘要

此篇論文主要是利用Microstrip antenna的架構設計兩隻寬頻天線。首隻天線是研究以一個有Microstrip antenna多重架構達到寬頻應用的手持式寬頻數位電視天線，藉由把三個具有臨近共振頻帶的微帶天線組合在一起，其在UHF頻帶的寬頻特性就可達到。由於是要裝置於手持式的設備中，所以天線的體積不能過大。為了縮小其體積，將傳統式的patch antenna的一端利用金屬牆短路，如此就可將原本需要二分之一波長共振的天線縮小成只需利用四分之一波長的尺寸就可以工作，另外再利用高介電系數的陶瓷材料可使其再縮小根號εr倍的體積。第二隻天線建立在patch antenna array的架構中，研究利用改變各單體間的間距與饋入相位差達到指向性天線的要求。為了達到最大能量的饋入，研究利用模擬軟體計算線阻抗使得傳輸線輸入阻抗達到50歐姆的匹配。並且藉由增加各單體的高度，達到增加頻寬的效果。
Wheeler cap method是一個簡單且標準量測小形化天線效率的方法，研究藉由合適的蓋子量出天線的效率並與無反射室量測的peak gain做為比較。

關鍵字

數位電視天線 ； 陣列天線 ； 效率

並列摘要

In this thesis, we propose to design two broadband antennas based on the structure of Microstrip antenna. The first antenna is investigated and is stacked with three individual microstrip antennas which have close resonate frequency to create a wideband DVB-H antenna in UHF band. Because this antenna is embedded to the handheld device, due to the volume needs to be small. In this work, we shorten the patch antenna with ground in the one side and then reduce the traditional patch antenna resonating at half of wavelength to be quarter wavelength of the frequency of system. Another technique is using ceramic material with the high dielectric constant to reduce volume. The second antenna is to form a patch antenna array, we investigate to adjust space and phase shift between each element to reach the directional antenna requirement. For having the maximum power feeding to each element, we make the transmission line matching at 50Ω。
Wheeler cap method is a simplest and standard method for measuring the efficiency of electrically-small antenna. We can get the measured result from the proper cap and then compare with peak gain measured in chamber.

並列關鍵字

efficiency ； DVB-H antenna ； array antenna

參考文獻

[1] Jean-Francois Zurcher and Fred E. Gardiol, “Broadband Patch Antennas,” ARTECH HOUSE, inc. 1995

[4] Ville Ollikainen and Chengyuan Peng, “A Handover Approach to DVB-H Services,”

Multimedia and Expo, 2006 IEEE International Conference Page(s):629 – 632,

July 2006

[9] Gwo-Yun Lee, Tzung-Wern Chiou and Kin-Lu Wong“Broadband Stacked Shorted Patch Antenna for Mobile Communication Handsets,” Microwave Conference, 2001. APMC 2001. 2001 Asia-Pacific Volume 1, 3-6 Dec. 2001 Page(s):232 - 235 vol.1