简介:WereportthedepositionofNb2O5filmsonunheatedBK-7glasssubstratesusingremoteplasmasputteringsystem.Theremoteplasmageometryallowspseudoseparationofplasmaandtargetbiasparameters,whichofferscompletedepositionratecontrol.Usingappropriateoxygenflowrates,high-densityandlow-lossNb2O5filmsaredepositedwithratesupto0.49nm/s.Lowerdepositionrates(~0.026nm/s)canalsobeobtainedbyworkingatlowtargetcurrentandvoltageandatlowpressure.Nb2O5filmsdepositedatdifferentrateshavetherefractiveindexofabout2.3andtheextinctioncoefficientaslowas6.9×10-5.
简介:Anovelmethodfordesigningabeam-switchingantennawiththeplanedipoleispresented.Theantennaiscomposedofdoubledipolesplacedatthecenterofanactivesquarestructurethatisdividedinfourequalsectorsbymetallicsheets.Metallicpatchesattheoutsideofthestructureareusedtoenhancetheradiationperformanceoftheantenna.Ineachstep,thediodesinonesectorareon,whereasotherdiodesareoff.Thesectorwithoff-statediodesdefinesthedirectionoftheradiationpattern.AnantennamodelisdesignedonthesubstrateofFR4.Theproposedantennaoperatesfrom4.8GHzto5.5GHzwithgainof6.3dBiandF/B(fronttobackratio)of13.2dBiwhentheoperatingfrequencyis5.2GHz.Theantennaradiationpatterncanbesweptintheentireazimuthplaneinfourstepswitha3dBbeamwidthof90.Theresultsrevealthattheantennacouldbeusedinthebasestationofthewirelesscommunicationsystems.
简介:Becauseofrapiddevelopmentinnetworktechnology,Internetusagehasbecomewidespread.Itallowsuserswithsensingdevicestoobtainmedicaldataforhealthcare,suchasphysiologicalsignals,voice,andvideostreamsfromtelemedicinesystems,andtosendthehealthcaredatatoback-enddatabasesystems,creatingaubiquitoushealthcareenvironment.However,thisenvironmentrequiresawidespreadandsuitablenetwork.IPv6(Internetprotocolversion6)isthenext-generationInternetprotocolthatwillbetheprotocoloffuturenetworks;itimprovesmanyshortcomingsofIPv4.Inthispaper,weproposeanIPv6/IPv4U-home-caretestsystemandanalyzethenetwork’sparametersthoughaseriesoftestsbyadjustingnetworkparameterstofindtheoptimaldesignforapplicationsintheIPv6/IPv4U-home-careservicesoastoassuregoodperformanceandhighquality.
简介:Doubledataratesynchronousdynamicrandomaccessmemory(DDR3)hasbecomeoneofthemostmainstreamapplicationsincurrentserverandcomputersystems.Inordertoquicklysetupasystem-levelsignalintegrity(SI)simulationflowfortheDDR3interface,twosystem-levelSIsimulationmethodologies,whichareboard-levelS-parameterextractioninthefrequency-domainandsystem-levelsimulationassumptionsinthetimedomain,areintroducedinthispaper.BycomparingtheflowofSpeed2000andPowerSI/Hspice,PowerSIischosenfortheprintedcircuitboard(PCB)board-levelS-parameterextraction,whileTektronixoscilloscope(TDS7404)isusedfortheDDR3waveformmeasurement.Thelabmeasurementshowsgoodagreementbetweensimulationandmeasurement.ThestudyshowsthatthecombinationofPowerSIandHspiceisrecommendedforquicksystem-levelDDR3SIsimulation.