應用於無線區域網路之雙頻及寬頻天線設計

Designs of Dualband and Broadband Antennas for Applications in WLAN

陳文仁(Wen-Ren Chen)

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2004年)

摘要

目前，具較佳之全方向輻射、多頻且天線尺寸較小等特性之單極 (monopole) 天線及
具結構簡單、製作容易及高寬頻之共平面波導 (coplanar waveguide, CPW) 饋入型天線已
被大量研究並應用整合於單石微波積體電路 (monolithic microwave integrated circuit,
MMIC) 中。因此，本論文將根據理論分析與實驗量測方式來設計新型具單層、雙頻、寬
頻且小型化之單極或共平面波導饋入型天線。研究過程中，除利用天線模擬軟體進行分
析設計外，並將設計結果製成實體進行實驗量測取得包含回歸損耗比 (rerturn loss)、阻抗
頻寬 (impedance bandwidth)、輻射場型 (radiation pattern) 及增益等天線輻射特性值。
本論文中除詳細探討及分析証明在一個具雙平行「S」形狀之平面單極天線結構上，
加入一段金屬細補片 (thin metallic patch) 及使用非對稱之天線結構安排方式能有效改善
天線的阻抗匹配情形 (回歸損耗比可至 -40dB)、增加阻抗頻寬 (可達 73.5%)，並達到多頻
諧振及將天線小型化 (16x14.5x1.6 mm3)的設計結果外，另在共平面波導饋入式天線設
計中提出利用挖槽孔 (slot) 方式來增加電流的路徑長度，以縮小天線的整體尺寸，並應用
調整電磁耦合量大小的方法來增減電性長度 (electrical length)，以產生諧振點頻率偏移、
增加阻抗頻寬及改變輻射場型之效果。所提出的二種天線設計皆可應用於 2.4 和 5.2 GHz
頻帶如藍芽 (Bluetooth) 及無線區域網路 (WLAN) 等通訊系統中。研究過程中，除分析上述
二種天線設計之設計原理及實驗結果外，並與相關文獻作比較以顯現所提出之設計技術
之特點。

並列摘要

The monopole antenna with characteristics of omni-directional radiation、multi-band and
smaller size, and the coplanar waveguide (CPW) feeding antenna with that of simple structrue,
easy to fabricate, and broadband, have been most investigated and utilized for integrating into
the monolithic microwave integrated circuit (MMIC). Thus, based on the theoretical analysis
and experimental study, this thesis proposes novel designs of the planar monopole antenna
and CPW-fed antennas, both with characteristics of single layer, dual-band operation,
broadband, and miniature size. In this study, not only use the antenna simulation software to
theoretically analysis the designed antenna, but also fabricate the proposed antenna to obtain
its measured radiation performance including return loss, impedance bandwidth, radiation
pattern and gain and so on.
This thesis explorative discuses and proves that adding a thin metallic patch and using a
unbalance structure arrangement in a parallel double 「S」 shaped monopole antenna can
effectively improve the impedance matching condition (less than -40dB), enhance impedance
bandwidth (more than 73.5%), produce multi-band operation, and miniaturize the antenna
size (16 x 14.5 x 1.6 mm3). In addition, for CPW-fed planar antenna design case, the
methodologies of both embedding slots into the patch to increase the effective electric length
and thus reduce the antenna scale, and adjusting the coupling conduction between the
radiation elements to shift the resonance locations, increase the impedance bandwidths, and
improve the radiation patterns, have been applied and discussed. Both of the proposed designs
are available to 2.4 and 5.2 GHz applications such as the Bluetooth and wireless local area
network (WLAN) communication systems. During the investigation process, in addition to
present the design principles and experimental results of the two proposed antennas, the
obtained results have also been compared with that from the literature.

參考文獻

[1] G.A. Deschamps, "Microstrip Microwave Antennas," Presented at the Third USAF

[3] D.M. Pozar, "Microstrip Antennas," Proc. IEEE, Vol.80, No.1, pp.79-81, January 1992.

[4] I.J. Bahl and P. Bhartia, Microstrip Antennas, Aretech House, Dedham, MA, 1980.

[5] K.R. Carver and J.W. Mink, "Microstrip antenna Technology," IEEE Trans. Antennas

[6] P.B. Katehi and N.G. Alexopoulos, "On the Modeling of Electromagnetically Coupled