臺灣博碩士論文加值系統

在本篇論文中，提出多種用於無線網路頻帶之寬頻及易於實現的F型天線設計。其中一種天線架構可靈活實現於各種不同機構中。
我們利用縮短短路板法、低共振頻率法設計平版倒F型天線並且提出一個輕薄短小的倒F暨單極天線設計，以上設計方式皆使用2.5D電磁模擬軟體。其中，所提出的縮短短路板法有較好的阻抗匹配特性，但是低共振頻率法卻可提供較大的頻寬。儘管如此，兩種平板倒F型天線皆可應用於現階段無線區域網路(2.4GHz)所使用的規格。實測的結果，低共振頻率法可達到-10dB頻寬304MHz(12.4%)，範圍從2.332GHz到2.636GHz，最大輻射增益為3 dBi。縮短短路板法所展示的頻寬可到達220MHz(9%)，範圍由2.36GHz到2.58GHz，最大輻射增益為2.5dBi。除此之外，倒F暨單極天線為一個三頻天線，在2.4GHz頻帶有210MHz(8.5%)頻寬，另外還有一個在5GHz 2940MHz(50.4%)的頻寬，可供給整個5.2GHz和5.8GHz頻帶收發使用，因此可符合無線區域網路(IEEE802.11a,b,g)之規範。
利用三個相近的單極天線的共振，設計倒F暨單極天線，本論文所展示的倒F暨單極天線包含了一個倒F型天線、一個單極天線和一個迴圈共振體，這三個相近共振頻率可造成第二及第三個頻帶，由4.36到7.3GHz將近3GHz的頻寬。所量測到的天線輻射增益在2.4-, 5.2-, 5.8-GHz分別為0, 1.44, 1.12dBi。事實上，所設計的倒F暨單極天線可達到寬頻、微小化、低反射損耗和簡易製作等特點，所模擬設計的天線都與實作相符合。

In this thesis, we propose novel design of broadband and easy fabrication F antenna for WLAN band. One of the antenna structures is flexible and capable of being realized in various application cases.
Reduced short circuit plate (RSC), low resonant frequency (LRF) for PIFA design and IFMA (Inverted F and Monopole antenna) are applied to design a compact F antenna with the aid of a 2.5D field simulator, IE3D. Not only does RSC give better impedance matching, but the LRF provides broader bandwidth. Both designed PIFAs are operated at wireless LAN of IEEE802.11b,g. Measurements indicate that the LRF achieves -10dB bandwidth up to 304MHz(12.4%) ranging from 2.332GHz to 2.636GHz, and the peak gain is 3 dBi. The RSC has a bandwidth up to 220MHz(9%) ranging from 2.36 GHz to 2.58 GHz, and the gain is 2.5 dBi. Besides, the IFMA is a triple band antenna that has 210MHz(8.5%) bandwidth at 2.4 GHz and 2940MHz(50.4%) at 5GHz that can apply in whole 5GHz, 5.2- and 5.8- GHz.
We apply three adjacent resonance of monopole to design IFMA. The presented IFMA that consist of a inverted F type antenna, a monopole and a loop antenna can reach almost 3GHz bandwidth from 4.36 to 7.3 GHz for the second and third band applications. The measured antenna gains are about 0, 1.44, and 1.12 dBi for the 2.4-, 5.2-, 5.8- GHz frequencies, respectively. Actually, our design F antennas reach broadband, miniaturization, lower return loss, and easy to fabricate. Our simulations we design all match to measurements.

Chapter 1 Introduction.................................1
1.1 Motivation......................................1
1.2 Outline of the Thesis...........................2

Chapter 2 Basic Theory of Planar Inverted F type Antenna...3
2.1 Inverted-L Antenna..................................3
2.2 Radiation Pattern of ILA ...........................7
2.3 Patch Antenna......................................12
2.4 Quality Factor, Bandwidth, and Efficiency of Patch...14
2.5 Input Impedance of Patch...........................17
2.6 PIFA(Planar Inverted F Antenna)....................19

Chapter 3 Using Resonance of PIFA to Design...............23
3.1 Design by Resonant Frequency for λr/4(RF-λr/4).....23
3.1.1 Design Rule......................................23
3.1.2 Feed Point.......................................24
3.2 Matching at Resonant Frequency.....................27
3.3 Reduce Short-Circuit to Design (RSC)...............29
3.4 Lower Resonant Frequency(LRF)......................33
3.5 Radiation Pattern..................................36
3.6 Summary............................................38


Chapter 4 Triple Band Inverted F and Monopole Antenna.....42
4.1 Printed Monopole Antenna...........................42
4.2 Bending Printed Monopole Antenna...................44
4.3 Inverted F type and Monopole Antenna(IFMA).........47
4.4 Fabrication and Radiation Pattern..................54
4.5 Summary............................................57

Chapter 5 Conclusion and Future Work......................58
5.1 Conclusion.........................................58
5.2 Future Work........................................59

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