相控阵天线讲的深入浅出，很有参考价值1Radiation11.1TheEarlyHistoryofElectricityandMagnetism11.2JamesClerkMaxwell,TheUnionofElectricityandMagnetism81.3RadiationbyAcceleratedCharge101.4ReactiveandRadiatingElectromagneticFields18References182Antennas192.1TheEarlyHistoryofAntennas192.1.1ResonantElectricCircuit202.1.2HeinrichHertz:TheFirstAntennaandRadioSystem232.1.3GuglielmoMarconi,theDawnofWirelessCommunication28viCONTENTS2.1.4AftertheFirstTransatlanticTransmission352.1.5Directivity402.2AntennaDevelopmentsDuringtheFirstWorldWar442.3AntennaDevelopmentsinBetweentheWars472.3.1Broadcasting472.3.2Microwaves482.4AntennaDevelopmentsDuringtheSecondWorldWar502.4.1Radar502.4.2OtherAntennaDevelopments602.5Post-WarAntennaDevelopments722.5.1FrequencyIndependentAntennas732.5.2HelicalAntenna742.5.3MicrostripPatchAntenna752.5.4PhasedArrayAntenna76References803AntennaParameters833.1RadiationPattern833.1.1FieldRegions843.1.2Three-DimensionalRadiationPattern873.1.3PlanarCuts913.1.4PowerPatternsandLogarithmicScale963.1.5DirectivityandGain983.1.6Reciprocity1013.1.7AntennaBeamwidth1023.2AntennaImpedanceandBandwidth1033.3Polarisation1073.3.1EllipticalPolarisation1073.3.2CircularPolarisation1093.3.3LinearPolarisation1103.3.4AxialRatio1103.4AntennaEffectiveAreaandVectorEffectiveLength1123.4.1EffectiveArea1123.4.2VectorEffectiveLength1143.5RadioEquation1153.6RadarEquation1173.6.1RadarCross-Section118References120CONTENTSvii4TheLinearBroadsideArrayAntenna1234.1ALinearArrayofNon-IsotropicPoint-SourceRadiators1234.2PlaneWaves1244.3ReceivedSignal1264.4ArrayFactor1314.5SideLobesandGratingLobes1314.5.1FirstSide-LobeLevel1314.5.2GratingLobes1324.6AmplitudeTaper133References1355Designofa4-Element,Linear,Broadside,Microstrip

在日常工作中，钉钉打卡成了我生活中不可或缺的一部分。然而，有时候这个看似简单的任务却给我带来了不少烦恼。 每天早晚，我总是得牢记打开钉钉应用，点击"工作台"，再找到"考勤打卡"进行签到。有时候因为工作忙碌，会忘记打卡，导致考勤异常，影响当月的工作评价。而且，由于我使用的是苹果手机，有时候系统更新后，钉钉的某些功能会出现异常，使得打卡变得更加麻烦。 另外，我的家人使用的是安卓手机，他们也经常抱怨钉钉打卡的繁琐。尤其是对于那些不太熟悉手机操作的长辈来说，每次打卡都是一次挑战。他们总是担心自己会操作失误，导致打卡失败。 为了解决这些烦恼，我开始思考是否可以通过编写一个全自动化脚本来实现钉钉打卡。经过一段时间的摸索和学习，我终于成功编写出了一个适用于苹果和安卓系统的钉钉打卡脚本。