Designation:A893/A893M−03(Reapproved2015)StandardTestMethodforComplexDielectricConstantofNonmetallicMagneticMaterialsatMicrowaveFrequencies1ThisstandardisissuedunderthefixeddesignationA893/A893M;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thistestmethodcoversthemeasurementofthecom-plexdielectricconstantofisotropicferritesforextremelyhigh-frequencyapplications.1.2ThevaluesstatedineitherSIunitsorinch-poundunitsaretoberegardedseparatelyasstandard.Thevaluesstatedineachsystemmaynotbeexactequivalents;therefore,eachsystemshallbeusedindependentlyoftheother.Combiningvaluesfromthetwosystemsmayresultinnon-conformancewiththestandard.Withinthisstandard,SIunitsareshowninbrackets.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappro-priatesafetyandhealthpracticesanddeterminetheapplica-bilityofregulatorylimitationspriortouse.2.SummaryofTestMethod2.1Inanisotropicdielectricmediumwithasteadyelectricfield,E,theelectricdisplacement,D,isgivenbytheequation:D5kε0E(1)where:ε0=permittivityoffreespaceandk=dielectricconstant.Ifthemediumissubjectedtoanalternatingelectricfield,theelectricdisplacementisnotnecessarilyinphasewiththefield.Thisfactmaybeexpressedmathematicallybytakingkasacomplexquantity.Ifwewritek=k'−jk",theimaginarypart,k",determinesthedissipationinthemedium.2.2Thistestmethodusesacavityperturbationtechniqueasameansofseparatingelectricfrommagneticeffects.Quanti-tiesthatmustbemeasuredaretheresonancefrequency,f,ofthecavitywithandwithoutthesample,theloadedQofthecavitywithandwithoutthespecimen,andthecavityandspecimendimensions.2.3Thespecimenisintheformofarodandisplacedparalleltothemicrowaveelectricfieldinaregionofsubstan-tiallyuniformelectricandzeromicrowavemagneticfiel...
