- 學位論文
應用於無線區域網路與超寬頻之共面波導饋入平面天線之設計
Design of Coplanar Waveguide-fed Planar Antennas for Wireless Local Area Network and Ultra-wideband Applications
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摘要
在本論文中，提出了三個共面波導饋入之新型平面天線設計。這些所提出的天線可以應用於無線區域網路 IEEE 802.11 a/b/g與超寬頻無線傳輸系統。 首先，為使用於無線區域網路 IEEE 802.11 a/b/g頻段，提出了具備一對T型匹配端子之雙頻開槽天線。有著寬闊面輻射之特性，此天線在操作頻段內之增益變化小於1dB且最大增益在2.4-2.5 GHz頻段和5-6 GHz頻段分別有3dBi和4.5dBi左右。 第二，本論文提出了一簡單且小型化之超寬頻(3.1-10.6GHz)之槽孔天線其亦可以延伸至具備頻帶阻絕的設計。此天線由一個矩形槽孔和T型激發端子組成。設計上，槽孔面積可縮小至13 x 23 mm2。討論了以模態為基礎之場型分布及其所對應的輻射場型之相關性。最後，亦提出三種進一步的頻帶阻絕於5-6 GHz之設計。 第三，提出了覆蓋無線區域網路IEEE 802.11 b/g (2.4-2.5GHz)與超寬頻(3.1-10.6GHz)且具有禁止頻帶於2.5-3.1 GHz之矩形單極天線之設計。此天線的寬頻特性是藉由漸開技巧達成。一組放置於單極天線上半部之狹縫槽設計成功地達到所需要的頻帶阻絕功能。相較於線性漸開的方式，圓形漸開方式可提供一較寬頻之頻寬及較佳之相位線性度。 第四，將探討超寬頻天線於頻域和時域之特性並將基本原理及重要公式作一整理與推導，並且述敘了對於時域研究藉由網路分析儀之量測方法。本論文所提及之矩形槽孔天線與狹縫槽負載之圓形漸開單極天線被用來分析其在某些平面切面在頻域和時域的特性。實驗結果顯示對於上面所提及的兩個天線，只有些微的脈衝波失真，其保真度之值介於0.8至0.96之間。
並列摘要
In this thesis, three novel coplanar waveguide (CPW)-fed planar antennas are presented. These proposed antennas can find applications in WLAN IEEE 802.11a/b/g and ultra-wideband (UWB) wireless systems. First, design of a dual-band slot antenna with a pair of T-match stubs with applications for WLAN IEEE 802.11a/b/g uses is investigated. With the broadside radiations, the proposed antenna carries a stable in-band gain variation within 1 dB with peak gains around 3 dBi and 4.5 dBi in the 2.4-2.5 GHz and 5-6 GHz bands, respectively. Secondly, a simple and compact UWB (3.1-10.6GHz) aperture antenna with extended band-notched designs is presented. The antenna consists of a rectangular aperture on a PCB ground plane and a T-shaped exciting stub. A compact aperture area of 13 x 23 mm2 is achieved. The correlation between the mode-based field distributions and radiation patterns is discussed. Three advanced band-notched (5-6 GHz) designs are also presented. Thirdly, rectangular monopole antennas covering IEEE 802.11 b/g (2.4-2.5GHz) and UWB (3.1-10.6GHz) are designed with a notched band of 2.5-3.1 GHz. The wideband characteristics are achieved by tapering, technique. A pair of slits is inserted to the upper part of the monopole to obtain the notched band function. Compared to linear tapering method, the circular tapering method provides both wider bandwidth and better phase linearity. At last, basic principles for characterizing UWB antennas in both frequency and time domains are summarized and measurement methods using network analyzers are also given. Characteristics of the developed rectangular aperture antenna and slit-loaded circular-tapered monopole antenna are then examined in time and frequency domain at certain plane cuts. The experimental results show slight pulse distortion, with goof fidelity values of 0.8 to 0.96 for the two proposed antennas.
參考文獻
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