pifa天线(38)

1、以上天线都具有低剖面以上天线都具有低剖面(Low-Profile )特点特点现代通信面临的挑战现代通信面临的挑战# Signal Reliability# Minimize signal loss# Combat multipath fading effects# Power requirements# Miniaturization: Low Profile# Data rates# Frequency utilization1。The length of the patch (L) is typically about a third to a half of a free- space

2、wavelength (), .2。The dielectric thickness is in the range of 0.003 to 0.5. 3。A commonly used dielectric for such antennas is polytetrafluoral ethylene (PTFE), which has a relative dielectric constant of about 2.5.polytetrafluoral ethylene聚四氟乙烯聚四氟乙烯1. They are low-profile antennas.2. They are easily

3、 conformable to nonplanar surfaces. Along with their low profile this makes them well suited for use on high-performance airframes.3. They are easy and inexpensive to manufacture in large quantities using modern printed-circuit techniques.4. When mounted to a rigid surface they are mechanically robu

4、st.5. They are versatile elements in the sense that they can be designed to produce a while variety of patterns and polarizations, depending on the mode excited and the particular shape of patch used. 6. Adaptive elements can be made by simply adding an appropriately placed pin between the patch and

5、 the ground plane. Using such loaded elements, theantenna characteristics can be controlled. Transmission Line Model for Microstrip Antennas Cavity Model for Microstrip Antennas 现代移动通信对天线的要求主要为以下几方面： 1。小尺寸。 (Compact in size) 2。轻重量。(Light in Weight) 3。与设备共形。(Conformity with structure) 4。全向辐射。(Omni-Di

6、rectional) 5。多频带工作。(Multi-Band Operation) 6。 低造价。(Low Fabrication Cost) Advantages The PIFA has many advantages： easy fabrication, low manufacturing cost, and simple structure. Disadvantages But the major disadvantage keep the basic PIFA from diverse application is its narrow bandwidth, The major li

7、mitation of many low-profile antennas is narrow bandwidth. Typical conventional PIFAs have a 5% bandwidth, but advanced designs offer wider bandwidth.where f u and f l are upper and lower frequency of bandwidth, f r is resonant frequency, Q is quality factor,R is loss component of antenna, L is indu

8、ctive component of antenna, C is capacitive component of antenna,S is volume of antenna.*The basic PIFA consists of a ground plane, a top plate element, a feed wire attached the ground plane and the top plate, and a shorting plane that is connected between the ground and top plate. *In general, the

9、most frequently used method to broaden the bandwidth is to raise the height of shorting plane that is increasing the volume 2. 尽从理论上我们可以把PIFA天线作各种近似，但精确的分析必须应用数值分析的方法： 主要数值方法有：矩量法（MOM），有限元（FEM）法，时域有限差分方法（FDTD）。工作频率方向性相对带宽当接地板的尺寸为0.8时PIFA天线的相对工作带宽为0.8%除了增加接地板与上部辐射板之除了增加接地板与上部辐射板之间的间隙以外，展宽间的间隙以外，展宽PIF

10、A天线带天线带宽的技术还有宽的技术还有1。使用附加金属贴片的双谐。使用附加金属贴片的双谐 振电路技术。振电路技术。2。加载高介电常数介质。加载高介电常数介质3。加入贴片电阻以增加天线。加入贴片电阻以增加天线 负载，降低负载，降低Q值值 4。采用斜边顶板结构，。采用斜边顶板结构， 如图如图 示，辐射带宽可达示，辐射带宽可达16%DESIGN OF A COMPACT PIFA FOR MOBILE PHONES*B.C. Kim, J.D. Park , and H.D. ChoiRadio & Broadcasting Technology Laboratory, ETRI161 Ga

11、jong-dong, Yuseong-gu, Daejeon 305-350 KOREAE-mail : bckimaetri.re.krGSM:Global System for Mobile; DCS:Digital Cellular Sytem;PCS: Personal Communication System; IMT: International Mobile Telecommunication ISM: Industrial , Scientifical, MedicalChromosome 染色体Mutate 变异计算结果2。1GHHz-2.56GHz电压驻波比小于2的带宽46

12、0MHz19.5%Internal PIFA for 2.4=5 GHz WLANapplicationsY.J. Cho, Y.S. Shin and S.O. ParkELECTRONICS LETTERS 5th January 2006 Vol. 42 No. 12.4GHz.110MHz 4.6%5.GHz 900MHz 18%Optimization of PIFA-IFA Combination in HandsetAntenna DesignsZhan Li and Yahya Rahmat-Samii,IEEE TRANSACTIONS ON AP VOL. 53, NO.

13、5, MAY 2005 p.1770 inverted “F” antenna (IFA)Multiantenna development inone handset has become more and more common.Integrated Planar Multiband Antennas for Personal Communication Handsets IEEE TRANSACTIONS ON AP, VOL. 54, NO. 2, FEBRUARY 2006 p.384 开缝可以使PIFA天线工作在多个频率下。Integrated planar multi-band a

14、ntennasInternal Shorted Patch Antenna for a UMTS Folder-TypeInternal Shorted Patch Antenna for a UMTS Folder-TypeMobile PhoneMobile Phone IEEE TRANSACTIONS ON AP, VOL. 53, NO. 10, OCTOBER 2005 p.3391UniversalMobile Telecommunication System (UMTS)(1920 2170 MHz）Multiband PIFA for WLAN Mobile Terminal

15、sIEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 4, 2005 p.349开缝双频天线A Miniaturized Hilbert PIFA for Dual-Band MobileWireless ApplicationsIEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 4, 2005p. 59Hilbert geometry 是一种分形几何形状是一种分形几何形状Meandered Multiband PIFA WithCoplanar Parasitic Patches IE

16、EE MICROWAVE AND WIRELESS COMPONENTS LETTERS, VOL. 15, NO. 10, OCTOBER 2005 P.630INVESTIGATIONS INTO PERFORMANCES OF INVESTIGATIONS INTO PERFORMANCES OF SINGLE LAYER AND STACKED CONFIGURATIONS SINGLE LAYER AND STACKED CONFIGURATIONS OF MULTI-BAND PIFA ANTENNAOF MULTI-BAND PIFA ANTENNADESIGN OF A COM

17、PACT PIFA FOR MOBILE PHONES DESIGN OF A COMPACT PIFA FOR MOBILE DESIGN OF A COMPACT PIFA FOR MOBILE PHONES P.809PHONES P.809Single Feed Compact Quad-Band PIFA Antenna for Wireless Communication ApplicationsIEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 53, NO. 8, AUGUST 2005 2631Compact slotted

18、 planar inverted-F RFID tagmountable on metallic objectsELECTRONICS LETTERS 24th November 2005 Vol. 41 No.集总参数元件加载天线In most applications, the chip resistance is found to be in the range of3150 O, and reactance in the range of 20050 O (capacitive).折线和环形柱PIFA天线IEEE，APS 2005, P.508三角形PIFA天线Dual-Frequency Triangular Planar Inverted-F AntennaIEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 53, NO