共平面波導超寬頻天線之研究

Study of CPW Ultra-Wideband Antennas

徐立哲(Li-Jhe Syu)

指導教授 ： 陳立軒 ； 林文寬

義守大學/電機資訊學院/電子工程學系/碩士(2016年)

摘要

本論文提出具帶拒功能的超寬頻天線，所提出之天線架構除了滿足超寬頻天線規範的頻段(3.1 GHz-10.6 GHz)外，同時為了避免超寬頻天線與WLAN、X-band 衛星通信、ITU 8-GHz共存的頻段產生互相干擾，因此加入帶拒功能。本研究所提出之天線是使用FR4基板，且天線為共平面波導饋入，結構簡單。
共平面波導超寬頻天線是設計在介電常數為4.4的FR4基板上，基板尺寸為30×30×0.8mm3，天線的接地面連接，在上半部的接地面使用了斜角設計來達到良好的阻抗匹配，在斜角下方加入了階梯設計，可以使得7GHz-8GHz頻段的S11達到 -10dB以下，矩形貼片天線下半部的階梯設計是用來將10GHz的頻寬拉大到11GHz，而上半部的斜角設計是用來拉大4GHz的頻寬。帶拒功能則是利用在下方接地面所延伸出來的I形寄生元件與L形寄生元件，在5.5 GHz時，大部分的電流都被I形寄生元件所吸收，而在7.5 GHz時，大部分的電流都被L形寄生元件所吸收，因此產生帶拒功能。天線符合超寬頻天線的規格，加入寄生元件成功阻隔5.5 GHz與7.5 GHz的頻段，輻射場型呈現全向性的趨勢。模擬與實作的結果顯示天線具有穩定的輻射方向。

關鍵字

共平面波導 ； 超寬頻 ； 天線 ； 帶拒

並列摘要

CPW ultra-wideband antennas with notch characteristics are investigated in this study. The proposed ultra-wideband antenna works in the frequency range of 3.1 GHz-10.6 GHz. To avoid the interference with WLAN、X-band satellite communication and ITU 8-GHz, the afore-mentioned frequency band are notched. CPW antennas with simple structures are fabricated on FR4substrate with dielectric constant of 4.4.
The ground plane of ultra-wideband monopole antenna is connected and a bevel in the upper half of the ground plane is proposed to achieve good impedance matching. An oblique angle ladder pattern is to reach a better impedance matching in the frequency range between 7-8GHz and the lower part of the rectangular patch is to widen the bandwidth of 10GHz to 11GHz. The upper half of the bevel design is to widen the bandwidth of 4GHz and bands of UWB antennas are notched by adding parasitic elements. The I-shaped and L-shaped parasitic elements below ground plane are proposed for band notch. The currents are absorbed by the I-shaped parasitic elements in the frequency of 5.5 GHz and are absorbed in the 7.5 GHz by the L-shaped parasitic elements. Simulated and measured results show good agreement.

並列關鍵字

coplanar waveguide ； UWB ； antenna ； notch

參考文獻

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