简介:Akindofdual-band-stopfilterwithanunsymmetricalT-shapedefectedgroundstructure(DGS)isproposed.Thefilterhastwobandgapcentersat4.9GHzand7.35GHz,respectively,wherethetwocentrefrequenciesarejustthesecondandthirdharmonics2.45GHz.Thefilterswithhighband-stopperformanceandwidebandspurioussuppressioncanbeachievedbycascadingminiaturizedunsymmetricalT-shapeDGS.Theattenuationofthree-cascadedT-shapeDGSfilteris30.77dBat4.9GHzand17.96dBat7.35GHzrespectively.Theaboveexperimentalresultsareingoodagreementwiththesimulationresults,especiallyforthethirdharmonic.
简介:InviewofthelimitationsofaRn-GnmodelinthelowfrequencyrangeandthedefectsofanEn-Inmodelincommonusenow,thispaperbuildsacompleteEn-Inmodelaccordingtothetheoryofrandomharmonic.Theparametersforthelow-noisedesignsuchastheequivalentinputnoisyvoltageEns,theoptimumsourceimpedanceZsoptandtheminimumnoisefigureFmincanbecalculatedaccuratelybyusingthisEn-Inmodelbecauseitconsidersthecoherencebetweenthenoisesourcesfully.Moreover,thispaperpointsoutthatitwillcausethemaximum30%miscalculationwhenneglectingtheeffectsofthecorrelationcoefficient7.Usingtheseries-seriescircuitsasanexample,thispaperdiscussesthemethodsfortheEn-InnoiseanalysisofelectroniccircuitspreliminarilyanddemonstratesitscorrectnessthroughthecomparisonbetweenthesimulatedandmeasuredresultsoftheminimumnoisefigureFminofasinglecurrentseriesnegativefeedbackcircuit.
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