本論文設計一個PIFA天線，目的在將天線元件縮小化，應用於802.11a/b/g無線區域網路及802.15藍芽標準的雙頻(2.402-2.483GHz、5.15-5.825GHz) 天線，以支援行動電話及其相關的小型行動裝置或滿足其它ISM頻段產品的需求。
此天線的輻射本體為立體倒F型的PIFA天線，透過對PIFA天線的立體化將天線縮小於印刷電路板(PCB)的板邊附近，其目的是讓輻射天線能遠離金屬元件(如speaker、camera..等)的干擾，讓天線附近區域能夠淨空並且將能量輻射出去。所以本論文的天線本體也置放於PCB的板邊，以符合一般商用產品的實際使用方式。另外，使用立體PIFA天線的優點包括比較不佔PCB的空間，雖然此一設計的實作上需要利用到機械加工，但因此天線的最小尺寸是0.2mm，不需要使用精密的機械來加工。又天線本體採用便宜的馬口鐵製作，整個天線的製作並不需要花很多成本且能達到節省空間的目的。
為設計立體倒F型PIFA天線，首先將輻射本體藉由短路接腳而引進電感，並且將平面天線挖出很多的槽孔(slot)形成曲折(meander)的方式，讓天線能操作在四分之一波長，本論文並探討槽孔參數對於天線特性的影響。
此外，吾人採用缺陷型接地結構(DGS)的方法來改善2.4GHz和5GHz的頻寬，特別是2.4GHz處頻寬的增加，由於PIFA天線的缺點是當其操作頻率越低則頻寬愈窄，一般增加頻寬的常用方式包括增加天線的高度，但這和縮小化的目標矛盾。本論文改採用DGS的方法，及在天線本體正下方的FR4接地面，將地挖除2.5X11mm2的面積，其結果使得低頻2.4GHz頻段增加了22MHz的頻寬，高頻的部份則增加了126Mhz的頻寬(S11<-10dB)。
我們也針對本天線的設計進行一些參數變化的完整探討，例如，天線短路接腳大小與距離、DGS高度與大小等，最後將天線縮小化至11X6X4mm3的體積，其頻寬和效能都能達到符合期望的要求。

This thesis is to design a miniature dual band antenna for 802.11 a/b/g wireless LAN (2.402 GHz ~ 2.483 GHz and 5.15 GHz ~ 5.825 GHz) and 802.15 Bluetooth (2.402 GHz ~ 2.483 GHz) by using the PIFA structure.  It can be applied for the products of mobile phones, miniature portable devices and other products with ISM band.

The proposed antenna is designed by using a three-dimensional inverted-F antenna structure. The antenna volume can be reduced by arranging the antenna close to the corner of printed circuit board, which keeps antenna away from any metal component (such as speaker, camera … etc.). Because of this structure, there is a clear area for the proposed antenna and antenna radiation can go out. To mimic this in this thesis, the antenna is placed at the corner of the PCB board similar as the actual commercial products in general.

The advantage of the three dimensional PIFA antenna occupies less PCB space usually. Although the proposed PIFA antenna needs machining to produce, the smallest dimension is about 0.2 mm only , thus it doesn’t need to use sophisticated machinery. In addition, the proposed antenna body uses cheap tinplate for production, which cost little .   

In order to design a three-dimensional planar inverted-F antenna of size 11X6X4 mm3 the rectangular patch is short circuited first by a shorting pin. Then several slits are introduced on the rectangular patch to form a meandering structure, of which the length is about one-quarter for the lowest resonant frequency.  The effects of these slit parameters to the antenna characteristics are also studied.

In addition, the idea of defected ground is employed to improve the bandwidth, especially 2.4G band. One of the disadvantages of the PIFA antennas is the small bandwith for the low band as compared with the corresponding monopole antenna. The initial PIFA design faces the issue that the frequency bandwidth of low band is not wide enough. Although there are several ways to further improve the bandwidth, such as increasing the height of the antenna, those that would increase the volume of the antenna is not considered suited for miniature devices. In this thesis, we uses defected ground  by excavating an area of 2.5X11mm2 out of the FR4 board ground right under the antenna. The results show that the bandwidth improvement~ 22MHz is achieved at the low band, 2.4GHz, and ~126MHz for the high band, 5.8G ( |S11|<-10dB). 

 The effects of several parameters of the PIFA antenna structure are investigated, which include the width and distance of the short-circuiting pin, the size of the defected ground, etc. Based on these analyses, the miniature PIFA antenna is successfully designed with the volume of the antenna limited to 11X6X4mm3 and its bandwidth and performance can meet the requirements of the expectations.

中文摘要................................................II
英文摘要................................................IV
第一章 序論.............................................1

1.1簡介.................................................1
1.2研究目的.............................................1
1.3論文架構.............................................5

第二章 倒F天小型天線介紹及設計...................6

2.1 簡介.......................................................6
2.2 倒F型天線設計原理及簡介......................... 6
2.2.1 矩型微帶天線原理.....................................7 
2.2.2 倒F型天線介紹........................................9
2.2.3 空腔模型..............................................11
2.2.4 微帶傳輸線之結構..................................13
2.3 倒F型天線縮小化設計.................................17
2.3.1 天線設計參數及流程................................17
2.3.2 槽縫長度參數決定..................................20
2.3.3饋入點與接地點參數決定.............................33
2.3.4 缺陷型接地對於頻寬影響............................39
2.3.5 天線最佳化完成結果................................53

第三章 天線量測與分析.......................................55

3.1 測試儀器及設備......................................55
3.2 天線特性量測與模擬比較..............................58
3.2.1 反射係數及電流方向................................58
3.2.2 輻射場形量測......................................61

第四章 結論.............................................65
圖目錄

圖2.1 矩型微帶天線結構圖……………………………………………8
圖2.2 平面倒F天線結構………………………………………………10
圖2.3 加入金屬短路板在相同頻率下的TM10模態電場示意圖……10
圖2.4 矩型微帶天線空腔模…………………………………………12
圖2.5 微帶線立體結構………………………………………………13
圖2.6 共平面波導立體結構…………………………………………14
圖2.7 槽線立體結構…………………………………………………14
圖2.8 微帶線PCB結搆圖……………………………………………15
圖2.9 50歐姆微帶線及PCB正視及側視圖…………………………16
圖2.10 50歐姆微帶線之S11響應圖…………………………………16
圖2.11天線設計流程圖………………………………………………19
圖2.12改變槽縫長度L1參數變化之雙頻天線正視及側視圖
(L=11mm，W=6mm，H=4mm，W1=0.15mm)……………………………23
圖2.13圖2.12加入槽縫長度W2參數變化之雙頻天線正視及側視圖
(L=11mm，W=6mm，H=4mm，L1=10.15mm，W1=0.15mm，La=0.15mm) …………………………………………………………………………24
圖2.14圖2.13加入槽縫長度L2參數變化之雙頻天線正視及側視圖
(L=11mm，W=6mm，H=4mm，L1=10.15mm，W1=0.15mm，W2=1.95mm，W3=0.15mm，L2=8mm，La=0.15mm)…………………………………25
圖2.15加入槽縫S1-S8參數變化之雙頻天線正視及側視圖
 (L=11mm，W=6mm，H=4mm，L1=10.15mm，W1=0.25mm，W2=1.95mm，W3=0.25mm，L2=8mm，La=0.15mm，Wb= 1.5mm，Lb=0.5mm)………………………………………………………………………26
圖2.16 加入槽縫參數X1-X8參數變化之雙頻天線正視及側視圖
(L=11mm，W=6mm，H=4mm，L1=10.15mm，W1=0.25mm ，W2=1.95mm，W3=0.25mm，L2=8mm，La=0.15mm，Wc=1.5mm，Lc=0.5mm)………26
圖2.17圖2.15及圖 2.16結合後之雙頻天線正視及側視圖 
(L=11mm，W=6mm，H=4mm，L1=10.15mm，W1=0.25mm ，W2=1.95mm，W3=0.25mm，L2=8mm，La=0.15mm，Wb= 1.5mm，Lb=0.5mm)…………………………………………………………………………28
圖2.18 改變槽縫長度L1參數變化之S11模擬比較…………………29
圖2.19 改變槽縫長度W2參數變化之S11模擬比較圖………………29
圖2.20 增加L2槽縫長度變化之S11模擬比較圖……………………30
圖2.21 加入槽縫S1-S8參數變化之S11模擬比較圖…………………30
圖2.22 加入槽縫X1-X8參數變化之S11模擬比較圖…………………31
圖2.23 結合S1-S8和X1-X8槽縫之S11響應圖………………………31
圖2.24 在3GHz、相位45度電流圖……………………………………32
圖2.25 在6.65GHz、相位0度電流圖…………………………………32
圖2.26 改變饋入腳與接地腳參數M1及接地腳寬度參數G之雙頻天線正視及側視………………………………………………………………35
圖2.27 改變饋入腳與固定接地腳M1距離的S11模擬比較…………36
圖2.28 改變饋入腳與固定接地腳M1距離之實部阻抗圖……………36
圖2.29 改變饋入腳與固定接地腳M1距離之虛部阻抗圖……………37
圖2.30 改變接地腳與固定饋入腳M1距離的S11模擬比較圖…………37
圖2.31 改變接地腳與固定饋入腳M1距離之實部阻抗圖……………38
圖2.32 改變接地腳與固定饋入腳M1距離之虛部阻抗圖……………38
圖2.33 改變G接地腳寬度的S11模擬比較圖…………………………39
圖2.34  PCB改變DGS參數Lg、Wg之雙頻天線正視及背面圖…………43
圖2.35 使用Lumped port分析之雙頻天線的正視圖…………………44
圖2.36 改變螺旋槽縫長度參數之雙頻天線正視及背面圖
(L=11mm，W=6mm，H=4mm，L1=10.15mm，W1=0.15mm ，W2=1.95mm，W3=0.15mm，W4=0.15mm，L2=8mm，L3=7.2mm，La=0.15mm，W5= 0.9mm，L4=1.9mm，F=1.5mm，G=1.5mm)………………………………45
圖2.37 改變螺旋槽縫長度、DGS、饋入點寬度參數之雙頻天線正視及背面圖(L=11mm，W=6mm，H=4mm，L1=10.15mm，W1=0.15mm ，W2=1.95mm，W3=0.15mm，W4=0.15mm，L2=8mm，L3=7.2mm，La=0.15mm，W5= 0.9mm，L4=1.9mm，F=0.5mm，G=1.5mm，Lg=11mm，Wg=2.5mm)………………………………………………………………46
圖2.38 改變Wg與Lg的DGS寬度之反射係數模擬比較圖………………47
圖2.39 改變天線本體與DGS高度H參數之反射係數模擬比較圖……47
圖2.40 改變天線本體與非DGS高度H參數之反射係數模擬比較圖…48
圖2.41 DGS與非DGS的反射係數模擬比較圖…………………………48
圖2.42 de-embedding與移除接地腳之反射係數模擬比較圖………49
圖2.43 de-embedding與移除接地腳之實部阻抗圖…………………49
圖2.44 de-embedding與移除接地腳之虛部阻抗圖…………………50
圖2.45 lumped port之反射係數模擬圖………………………………50
圖2.46 lumped port之實部阻抗圖……………………………………51
圖2.47 lumped port之虛部阻抗圖……………………………………51
圖2.48 改變螺旋槽縫長度參數之反射係數模擬圖…………………52
圖2.49改變螺旋槽縫長度、DGS、饋入點寬度參數之
反射係數比較模擬圖……………………………………………………52
圖2.50 雙頻天線本體設計完成尺寸圖及三視圖，單位mm…………53
圖2.51 雙頻天線全部完成尺寸圖，單位mm…………………………54
圖3.1 雙頻天線本體實作圖……………………………………………55
圖3.2雙頻天線實作完成圖……………………………………………56
圖3.3 Agilent E5071C網路分析儀….………………………………56
圖3.4 3D天線量測實驗室………………………………………………57
圖3.5 3D天線量測實驗室近圖…………………………………………57
圖3.6 雙頻天線反射係數模擬與量測比較圖…………………………59
圖3.7 2.4G天線輻射本體表面電流的流向、相位128度……………60
圖3.8 5.4G天線輻射本體表面電流的流向、相位38度………………60
圖3.9 2.4G X-Y輻射場型圖……………………………………………61
圖3.10 2.4G X-Z輻射場型圖…………………………………………62
圖3.11 2.4G Y-Z輻射場型圖…………………………………………62
圖3.12 5.46G X-Y輻射場型圖…………………………………………63
圖3.13 5.46G X-Z輻射場型圖…………………………………………63
圖3.14 5.46G Y-Z輻射場型圖.………………………………………64
表目錄

表1.1 使用ISM國家的主要通道及功率位準………………………3
表2.1 PCB模擬設計參數表…………………………………………18
表3.1 量測及模擬的實驗結果 ……………………………………59

[1] Tae-Hyun.Kim, Dong-Chul.Park, “Compact dual-band antenna with double L-slits for WLAN operations,” Antennas and Wireless Propagation Lett., IEEE Vol. 4, 2005, pp.249-252. 
[2] H.S.Yoon, and S.O.Park, ”A dual-band internal antenna of PIFA type for Bluetooth/WLAN in mobile handsets,” Antennas and propaqation international symposium, 2007.IEEE, 9-15, June.2007, pp. 665-668.
[3] Young-Jun.Cho, Soon-Ho.Hwang, Ishida.O, Seong-Ook.Park, “Dual-band internal antenna of PIFA type for mobile handsets and the effect of the handsets case and battery,” Antennas and propaqation Society international symposium, 2005.IEEE, vol.1A, 3-8, July. 2005, pp.487–490.
[4] Soo.Liam.Ooi, Boon.Ping.Koh, Song.P, Lau.L, “From a Simple IFA to Dual Band PIFA,”Antenna Technology:Small Antenna and Novel metamaterials,2008.IWAT.2008,
International Workshop on , 4-6, Mar.2008, pp.386-389.
[5] Dong-UK.Sim, Jae-Ick.Choi, “A Compact Wideband Modified Planar Inverted F Antenna(PIFA) for 2.4/5-GHz WLAN,” Antennas and Wireless Propagation Lett., Vol.5, Issue.1, Dec.2006, pp.391-394.
[6] “802.11a/g Manufacturing Test Application Note-A Guide to Getting Started,”Agilent Technologies, 5988-6788EN, Mar.2003.
[7] “IEEE802.11 Wireless LAN PHY Layer(RF)Operation and, Measurement”Agilent Technologies, 5988-5411EN, Apr.2002.
[8] 禹帆，無線藍芽技術深入探討最新版，文魁資訊股份有限公司，
2001年11月。
[9] Hongfang.Cao, Xueguan.Liu, Wenfeng.Cai, Li.Zhang, “Analysis of a Triple-Band Planer Inverted-F Antenna,”Microwave and Millimeter Wave Tchnology,2008.ICMT 2008,International Conference on,Vol.1, 21-24, Apr.2008, pp. 407-409.
[10] Mikko.K.Karkkanien,“Meandered Multiband PIFA with Coplanar parasitic Patches,”Microwave and Wireless components Lett., IEEE Vol.15, Issue.10, Oct.2005, pp.630-632.
[11] I-Tseng.Tang, Ding-Bing.Lin, Wen-Li.Chen, Jui-Hong.Horng, Chi-Min.Li, “Compact Five-Band Meandered PIFA by Using Meandered Slots Structure,” Antennas and propaqation international symposium, 2007.IEEE,9-15, June.2007, pp.653–656.
[12]H.Y.Wang, S.Taylor, J.Simkin, J.M.Oakley, C.Emson and M.J Lancaster,“Simulation of Microstrip Small Antennas,”Antennas and Propaqation, 2001. Eleventh International Conference on(IEE conf.Publ.No.480),Vol.2, 17-20, Apr.2001, pp.611-614.
[13] Ding-Bing.Lin, I-Tseng.Tang, Ming-Zhang.Hong, Hsin-Piao.Lin,“A compact Quad-Band PIFA by Using Defected Ground Structure,” Antennas and propaqation international symposium, 2007. IEEE,9-15,June.2007,pp.4677-4680.
[14]Chul-Soo.Kim, Jun-Seok.Park, Dal.Ahn,Jae-Bong.Lim, “A novel 1-D periodic defected ground structure for planar circuits,” Microwave and Guided Wave Lett., Vol.10, Issue.4, Apr.2000, pp.131-133.
[15]陳武男，Defected Ground Structure--國科會計畫書整合，95年 C012-2
[16]蕭廣達，利用缺陷型接地結構之雙頻微型天線平面倒F天線設計，碩士論文，中央大學電機工程學系，2008年6月。
[17]林岡毅，小型化天線的分析與模擬，碩士論文，中山大學電機工程學系，2003年6月。
[18]李俊賢，應用於第三代行動電話之倒F天線設計，碩士論文，中央大學電機工程學系，2008年6月。
[19]崔逢叡，共平面波導饋入多分支單即天線特性研究，碩士論文，淡江大學電機工程學系，2008年6月。
[20] D.K.Cheng,Field and Wave Electromagnetic, 2nd Edition, Addision Welsey,1989.
[21] HFSS. Ansoft Corporation, Pittsburgh, PA.