| 摘要: | 本篇論文主要探討可適用LTE/WWAN多頻段單極天線設計，並尋找簡易設計方式下，讓此天線將呈現於能滿足無線廣域網路及長期演進的八頻工作頻段，且適合內置於智慧型手機。本文以單一路徑天線為基礎改良，產生0.86 GHz共振頻率點。然後，在單極天線路徑增加taper的調整機制，使高頻2.16GHz能有良好的阻抗匹配；接著，調整線寬線距，產生1.79GHz共振頻率點，並使它有良好的阻抗匹配。最後，利用並聯電感、串聯電容調整低頻阻抗匹配，使多頻段單極天線能夠在低、中、高頻都能有良好的阻抗匹配。滿足反射係數以-6 dB來定義，此多頻段單極天線足以涵蓋LTE700、LTE2300、LTE2500、GSM80、GSM900、DCS1800、PCS1900及UMTS等八個操作頻段。最後，提出簡單的結構、量產容易、成本低廉且可應用LTE/WWAN的印刷電路板天線。
本論文利用HFSS軟體進行模擬[23]，且天線面積大小僅為45 × 19 × 0.8 mm3。於FR4電路基板上，也實際測量天線之反射係數、輻射場型、增益以及輻射效率，來證實所模擬設計的平面天線確實可以適用，詳細的天線設計方式及實驗數據將在本論文中說明。; This thesis mainly discusses the designs LTE / WWAN multi-band monopole antenna for the applications of the wireless WAN and long-term evolution of eight frequency operation bands. The proposed antenna is also suitable for being embedded in smart mobile devices. In the thesis, based on a single path antenna improvement, the resonance frequency of 0.86 GHz is generated. Good impedance matching in the high band is obtained by adding a tapered strip to the antenna creating resonance at 2.16 GHz. Then, by adjusting the line width, resonance at 1.79 GHz and good impedance matching are obtained. Finally, by using shunt inductance and the series capacity adjustment, low frequency impedance matching is achieved. The proposed multi-band monopole antenna has achieved good impedance matching in the low, medium and high frequency bands. The multi-band monopole antenna can be operated in the eight operating frequency bands of the LTE700, LTE2300, LTE2500, GSM800, GSM900, DCS1800, PCS1900 and UMTS. Also the size of antenna is of only 45 * 19 * 0.8 mm3. Various antenna parameters, such as reflection coefficient, radiation patterns, gain, and radiation efficiency, are also measured to validate the proposed antennas. |
