本論文首先提出一種新型可達寬頻阻抗匹配的環形開槽天線,該天線是利用漸變式槽寬以達到寬頻的效果,可以比傳統的環形開槽天線有更佳的頻寬。本論文中亦提供了兩個進一步改善這個天線特性的做法。首先是改善天線之輸入阻抗匹配,進一步提升頻寬,我們在環形開槽結構所包圍之圓形金屬片上再開一個槽,使這個天線具有更佳的阻抗匹配,經模擬與實驗的驗證,該天線的共振頻率可以涵蓋100%的頻寬。接著,我們在漸變式環形開槽內加入隙環共振器。這是由於所提出天線的增益在高頻時會有約3-5 dB的衰減,並且造成與主波束大小相近的正交極化,因此利用隙環共振器來抑制造成交叉極化的電流,達到降低交叉極化位準並提高主波束增益的效果。 我們將所提出之天線架構設計在超寬頻技術規格所涵蓋的3.1-10.6 GHz頻段內,並經模擬與實驗驗證。最後,我們亦將該天線設計於60-GHz之多輸入多輸出架構下,並分析其工作效能。本論文所提出的寬頻天線設計確實可以廣泛應用在不同的頻段、不同的系統中。
This work provide a new antenna structure which can achieve wide band impedence matching, which has a widder band-width than traditional slot-ring antenna. In this thesis, we also provide two design guidelines for achieving better impedence matching and gain performance.. The first one is to improve impedence matching. We open another slot in the metal which is surrounded by the slot ring to form better impedence matching. Verified by simulation and experiment, this structure achieves 100% bandwidth. The structure mentioned has about 3~5 dB gain decrease in high frequency, and cause a big cross-polarization. Therefore the other is adding a split-ring resonator in the tapered structure, this structure can suppress cross-polarization efficiently and enhance co-polarization. By simulation and experiment, this structure can improve gain and supress cross-polarization in high frequency. Furthermore, we apply this structure to implement an Ultra-Wide Band Antenna (3.1~10.6GHz) , by simulation and experiment, this structure can be used in different frequency bands. Finally, we also apply thi structure in 60GHz MIMO system and analysis it’s performance. The wideband structure in this thesis can can be used widely in different frequency and different system..