槽線應用於多頻帶平面天線設計與改善角錐型號角天線的輻射特性之新型方法

Multiband Planar Antenna Using Slots and A Novel Method of Radiation Characteristics Improvements for Conical Horn Antenna

蕭名盛(Ming-Sheng Siao)

指導教授 ： 洪萬鑄

國立彰化師範大學/工學院/電信工程研究所/碩士(2016年)

摘要

在本論文中，我們提出兩種不同型態天線設計。第一種為槽線應用於多頻帶平面天線；第二種為改善角錐型號角天線的輻射特性之新型方法。
首先文中提出一種多頻帶平面天線被設計用於4G（LTE）和Wi-Fi熱點的應用，我們使用非對稱導體之有限地面的共平面波導的基本架構當主要信號傳輸路徑。能量由下方饋入至上方金屬面，產生出兩種電流方向，再利用耦合至下方槽線產生出多種路徑，以至於達到寬頻且多頻帶的效果。接著利用側邊的短路面可以調整天線的阻抗和電流的方向，達到所有頻帶內輻射場型一致性。
第二，在衛星通信系統中角錐型喇叭天線為一個主要的研究，為了滿足低旁瓣，對稱的要求，會使用效果良好的波浪型號角天線或者介質天線。但其製作上相對困難，成本也較一般型的高。為了解決這樣的問題，我們提出一種新型的改善方式，在角錐型號角天線裡擺放金屬圓錐使其產生變化，使旁辦降低與場型輻射有一致性和重疊性，再加上加入了金屬圓錐，相位中心變化差異不大，以利與碟型天線配合使用。最後使用電磁模擬轉體HFSS、CST與FEKO相互驗證，探討實作與模擬兩者結果。

關鍵字

槽線 ； 多頻帶平面天線 ； 特徵模態 ； 旁辦高低 ； 線性極化 ； 角錐型號角天線

並列摘要

In this thesis, we propose two different types of antennas design. The first is the multiband planar antenna using slots and the second is a novel method of radiation characteristics improvements for conical horn antenna.
The multiband planar antenna using slots is designed to be used for hotspots applications of 4G (LTE) and Wi-Fi. We use the asymmetrical conductor-backed finite-ground coplanar waveguide as the basic architecture and also acts as the main RF signal transmission path. The slots with different lengths and widths are placed in parallel with each other on the top and bottom ground planes to make multiple resonances at different frequencies, and therefore, to meet the broadband requirement. These slots are also used to control the current directions and thus, to determine a special characteristic mode that always radiate in the broadside direction for all working bands. In addition, the use the partial side wall, which act as a short path, can adjust the antenna input impedance and current directions for lower frequency band.
Second, we consider the pyramidal horn antenna used as the primary feed of the reflector antenna of satellite communication systems. To meet the requirements of lower sidelobes, symmetrical and resemble radiation patterns for E-plane and H-plane, we propose a new method to improve the radiation characteristics of the feed horn. We arrange a metal cone in the central axis of the pyramidal horn antenna and the slope of this metal cone is nearly the same as that of the feed horn. The phase center point of the feed horn due to this inserted metal cone changes very little so that the relation distance between the reflector and this associated feed horn nearly the same.
Finally, we will demonstrate our design methods and the measurement and simulation results are also discussed.

並列關鍵字

slot ； multiband planar antenna ； Characteristic Modes ； Sidelobe Level(SLL) ； Linear polarization ； Conical Horns

參考文獻

[1] N. I. Mohamed et al., “New Adjustable Slot Meander Patch Antenna for 4G Handheld Devices,” IEEE Antennas Wireless Propag. Lett.,vol. 12, pp. 1077 – 1080, 2013

[2] W. S. Chen et al., “A Compact Loop Antenna for 4G Mobile System,” 2013 IEEE Antennas and Propagation Society International Symposium (APSURSI), pp. 1712 - 1713, 2013

[3] D. M. Elsheakh, E.A Abdallah, “Compact Multiband Multifolded-Slot Antenna Loaded With Printed-IFA,”IEEE Antennas Wireless Propag. Lett.,vol. 11, pp. 1478 - 1481, 2012

[5] Abbas-Azimi M., Mazlumi F., Behnia F., “Design of Broadband Constant-Beamwidth Conical Corrugated-Horn Antennas,” IEEE Antennas and Propag. Mag. ,vol. 51, pp. 109-114, Dol 10.1109, 2009.

[6] Mei Qing Q., Wen Xuan T. et al., “Suppressing Side-Lobe Radiations of Horn Antenna by Loading Metamaterial Lens,” Scientific Reports 5 Num.9113, Dol 10.1038, 2015.