- 學位論文
具干擾防制的超寬頻單極天線元件之設計
Design of UWB antennas with band-notched characteristics
摘要
本研究致力於探討縮小型超寬頻(UWB)單極天線的頻帶凹陷設計，採用厚0.75mm 的FR4 基板，以相對介電係數為4.4，並運用IE3D 電磁模擬軟體進行模擬並和實驗相驗證。而UWB 具備高頻寬、低耗電及高速傳輸等特性，因此未來幾年裡，UWB技術將在電子產業裡扮演重要角色。 本論文針對Miniature 型天線加以設計同時考慮寬頻、干擾防制、縮小化及整合的探討，由於UWB技術頻帶為3.1G~10.6GHz，其中5G~6GHz 的頻帶內包含了其他的無線通訊用頻。為了避免UWB 手機實際與PC 之間進行傳輸時會干擾現有的無線區域網路(WLAN)，例如: IEEE 802.11a 以及HiperLAN/2。故本研究將Miniature 型天線的金屬單極貼片中設計ㄧ小槽孔，使其S11 在WLAN 的頻帶內產生凹陷的特性，以減少UWB 天線在5G~6GHz 頻帶所輸出的訊號，進而降低對於WLAN 的電磁干擾。然而在天線與手機整合的部份，吾人將Miniature 型天線及Band-Notched Miniature 型天線改變其接地面的尺寸，以模擬當天線實際與各尺寸的手機整合後所產生的效應。其天線單極面的寬度為11mm、長度為19.7mm，在電路的整合中佔很大優勢。 最後本研究探討改變天線接地面的尺寸來模擬當天線實際與各尺寸的手機整合後所產生的效應。模擬結果顯示對於各種尺寸的接地面，本研究所提出的天線可維持原先設計的特性，驗證了天線的可用性。其H-plane輻射場型在4~7 GHz中為全方向性，在3GHz及8GHz也趨近於全向性，因此相當具有實用性。在未來的研究可增加對於天線饋入方式的探討，使本研究在探討整合的部份更加完善。
並列摘要
In this thesis, the characteristics of the band-notched ultra wide band (UWB)monopole antennas are investigated. The antennas are designed and fabricated on the FR4 board, while the IE3D commercial software is utilized for the EM simulation. Due to the fact that UWB technology has the properties of wider bandwidth, low energy consumption and high transferring rate, it will play an important role in the electronic industry in the near future years. Thus, the objectives of this thesis focus on the design of a band-notched miniature UWB monopole antenna. The considerations of design the proposed monopole antenna include wide bandwidth, counter-interference, size minimizing and integrationwith the circuit on the PCB board. Because the bandwidth of UWB is from 3.1GHz to 10.6GHz which also includes other wireless communication(WLAN) bands from 5GHz to 6GHz, we have implanted a thin slot into the monopole antenna structure to prevent the interference between mobile phone and wireless communication such as WLAN of IEEE802.11a and HiperLAN/2. The band-notch will produce a notch effect in S11 of WLAN to decrease the interference between UWB and bandwidth from 5GHz to 6GHz in S11 parameter. The size of the band-notch antenna is just only 11mm x 19.7mm, and it is easy to integrate to the circuit of the mobile phone. In the thesis, the integration of the antenna and the mobile phone is also studied, for which the effects ofchanging the size of the ground upon the band-notch miniature antenna are investigated. The outcome of the simulation shows that the band-notchantenna maintains the original properties and characteristics even when the size of the ground plane is largely changed.