课程-天线原理第七讲

SchoolofElectronic&InformationEngineeringSouthChinaUniversitySouthChinaUniversityofResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineering7.1V形振SouthChinaUniversitySouthChinaUniversityof线。如V形振子和曲线振子，其思路是利用采用长度和角度可调的V形振子是最常用的选ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringV形振子的设计：根据工作频率，确定振子的SouthChinaUniversitySouthChinaUniversityofh采用矩量0.5h3的V形振子，在扇hh152()2h

388(

0.5hhhh11.5()2h

70.5(

1.5hhD2.95(h

ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineering计算表明：h=0.75的VSouthChinaUniversityof最大辐射方SouthChinaUniversityof角度ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineering折合振子（folded-dipole）是常用的线天线之一SouthChinaSouthChinaUniversityofResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofSouthChinaUniversityofL/ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaSouthChinaUniversityofResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversitySouthChinaUniversityofV1Z11I1Z12 V2Z12I1VinZ11IinZ120Z12Iin

Z Vin/IinZ11Z12I2/ Z2/ ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringV1V2SouthSouthChinaUniversityofI1I2

eeVe(Z11Z12)Ie ee VeZd

其中，Zd为单个对称振子的输入阻抗ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringV1V2 I1I2SouthChinaUniversityof相当SouthChinaUniversityof

Vo(Z11Z12)IoL/2的短路双导线输线。于VoIoZtIojZ0tan(L/Z11Z12其中，Zt、Z0分别为双

+--++--+

-

-+ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofV1VeVo，V2SouthChinaUniversityofI1IeIo，I2Ie+--++-V20时，VinV12Ve，VeVoVin2，IinI1Ie+--++-+-+- +-+-

Iin

I

VinVeResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityof VinVoVe Vin/2Vin/ SouthChinaUniversityof IoIe (1/2Zd1/Zt)Vin/ 2ZdZt2ZdZ11Z12ZtZ11

Z11ZdZt/2Z12ZdZt/2Z

Z

Z/2)2 Z/

4Z

Z ZdZt/ 2ZdZResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofYin1/Zin1/4ZSouthChinaUniversityof 2Z0tan(L/对于半波折合振子

Z tan 4Z=4 半波折合振子的输入阻抗是半波对称振子的4倍。ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofSouthChinaUniversityofResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofSouthChinaUniversityof折合振子常被用于FM广播的接收天ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaSouthChinaUniversityofZin(1c2d

(L/通常a1,a2远小于d，c近似cln(d/ln(d/a2

俯视 端视ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaSouthChinaUniversityofResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaSouthChinaUniversityofResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofSouthChinaUniversityofI1I0costI2I0sinResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringE1KI0costSouthChinaUniversityofE2KI0sint )KISouthChinaUniversityof0o0KE2EE1E2KI0(costsinsintcos)KI0sin(E1KI0E2KI0 E KI0cost+KI0sintKI0 ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringf()sin(SouthChinaUniversityof其形状为SouthChinaUniversityof时间变化8字形围角频率旋转，最大点旋数，场是圆极化的。ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofSouthChinaUniversityof cosf() coscos(cos ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaSouthChinaUniversityof5%的起伏

ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineering对于N层十字天线阵，增益可近SouthSouthChinaUniversityofResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaSouthChinaUniversityof典型结构，是金ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofSouthChinaUniversityofSouthChinaUniversityofSouthChinaUniversityof是一致的。ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringEEA-A点同EEA-A点同SouthChinaUniversityofSouthChinaUniversityofSouthChinaUniversityofResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofSouthChinaUniversityof ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineeringSouthChinaUniversityofSouthChinaUniversityofdG2.44d为层间距离，N为蝙蝠翼的层数ResearchInstituteofAntennas&RFTechniquesSchoolofElectronic&InformationEngineering与十字形振子Sou