简介:TheISMbandat2.4GHzhasmostlybeenusedorplannedforindoorsystems.Thisbandisalsoattractiveforoutdoorsystemsowingtotheeaseofthesystemdeployment,asnofrequencylicensesarerequired.Inthispaper,amultiplesuccessiveinternalmultireflectionmodelisusedtoestimatethecomplexelectricpermittivityat2.4GHzband.Toobtainthedata,measurementsareperformedat160MHzbandwidthcenteredabout2.4GHzusingavectornetworkanalyzer,whichprovidesinformationabouttheamplitudeandphaseoftransmissioncoefficient.Severalsamplesofeachmaterialaremeasuredandtheresultsvaryfromsampletosample.Ithasalsobeenfoundthatsomeobstacleshavepolarizationbehaviour.
简介:Theopticalparametersforthreesamplesofintrinsic,dopedSianddopedMg(AlxGa1-x)yIn1-yPpreparedbytheMOCVDonGaAssubstrateweremeasuredbyusingellipsometryandwerecalculatedbythetwo-layerabsorptionfilmmodel.Theresultsobtainedwerediscussed.Thegrownratesandthicknessofoxidiclayerontheintrinsic(AlxGa1-x)yIn1-yPsurfaceexposedintheatmospherewerestudied.Alineardependenceofoxidiclayerthicknessonthetimewasobtained.