近年來，隨著無線通訊的發展，被動元件需要能做到更小、更輕薄和成本更低。然而在通訊系統中，天線與濾波器與其他元件相比，使用了較大的面積。為了減少電路的面積，我們設計了一個電路架構，其同時具有濾波和輻射的特性。
本論文提出一操作在2.45 和5.2GHz之雙頻濾波天線設計，此濾波天線由一雙頻帶天線和三階半波長步階阻抗共振器所組成。為了實現雙頻帶濾波天線，本論文首先設計了雙頻帶單極天線，天線的架構有兩個分支，分別為天線的高、低頻共振路徑。另外在濾波器的架構上，我們利用四階雙頻帶通濾波器，其設計不但具有兩個通帶，同時在頻帶邊緣也形成多個傳輸零點，可以有效的抑制外頻雜訊的干擾。經由適當設計第三階共振器與地之間的指叉式電容架構與接地面挖槽，可有效達到良好的阻抗匹配。
多重輸出輸入(MIMO)無線通訊現在也已成為重要的議題。本論文將天線單元應用於MIMO架構中，為使其具有良好之隔離度，利用共振器的概念使S21達到小於-15dB。實作與量測之天線參數與實驗模擬結果將在本論文說明。

關鍵詞: 濾波天線、雙頻帶、帶通濾波器、步階阻抗共振器、多重輸入輸出

Recent advances in wireless communication have created a need for compact, low-cost, and low profile passive components. However, both antennas and filters are usually larger compared to other components in communication systems. To reduce the circuit size, we designed a single circuit module to provide both the filtering and radiation performances.
In this thesis, a dual-band filtering antenna operated at 2.45/5.2 GHz is proposed. The proposed filtering antenna is composed of a dual-band antenna and three stages of half-wavelength stepped-impedance resonators. To successfully develop the dual-band filtering antenna, a four pole dual-band band-pass filter and a dual-band monopole antenna are designed first. The dual-band monopole antenna has two paths for antenna to resonate at 2.45GHz and 5.2GHz. The four pole band-pass filter has two pass bands and multiple transmission zeros at the edge of band and it can suppress interference noise from outer band effectively. By properly adding the interdigital capacitor structure between the third resonator and ground, good impedance matching can be achieved.
Multiple-input multiple-output (MIMO) wireless communication has also become an important technology now. The antenna element in this thesis is further applied to MIMO antenna communication system. A resonator in the ground is designed to enhance the isolation of the MIMO antennas. Antenna parameters are measured and the experimental results are given and discussed in this thesis.

Key words: filtering antenna、dual-band、band-pass filter、stepped impedance resonator、MIMO

論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
目錄 v
圖次 vii
表次 ix
第一章 序論 1
1.1 研究動機及背景 1
1.2 研究方法 2
1.3 論文大綱 2
第二章 雙頻帶濾波器設計 3
2.1 步階阻抗共振器(Stepped Impedance Resonator)介紹 3
2.2 雙頻帶帶通濾波器架構 9
2.3 雙頻帶通濾波器之模擬結果 14
第三章 雙頻帶濾波天線之設計 15
3.1 雙頻帶天線之設計原理與架構 15
3.2 雙頻帶天線之模擬結果 18
3.3 雙頻帶濾波天線架構 20
3.4雙頻帶通濾波器與天線之整合與模擬結果 27
第四章 多重輸入輸出濾波天線設計 31
4.1 多重輸入輸出天線隔離方法介紹 31
4.2 多重輸入輸出濾波天線隔離度設計 32
4.3 MIMO雙頻帶通濾波天線之量測結果 35
第五章 結論 37
參考文獻 38

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