简介:Inrecentyears,microstripantennashavebeenmorewidelyappliedinsatellitecommunications,mobilephones,unmannedaerialvehicle(UAV),andweapons.Amicro-electro-mechanicalsystems-based(MEMS-based)high-resistancesiliconC-bandmicrostripantennaarrayhasbeendesignedfortheintelligentammunition.Thecenterfrequencyis4.5GHz.Acavityhasbeendesignedinsubstratetoreducethedielectricconstantofsiliconandhigh-resistancesiliconhasbeenusedasthematerialofsubstratetoimprovethegainofantenna.ItisveryeasytobemanufacturedbyusingMEMStechnologybecauseoftheimprovedstructureoftheantenna.Theresultsshowthatthegainoftheantennais8dBandvoltagestandingwaveratio(VSWR)islessthan2bytheanalysisandsimulationinhighfrequencystructuresimulator(HFSS).
简介:Inthiswork,ahardwareintrusiondetectionsystem(IDS)modelanditsimplementationareintroducedtoperformonlinereal-timetrafficmonitoringandanalysis.TheintroducedsystemgatherssomeadvantagesofmanyIDSs:hardwarebasedfromimplementationpointofview,networkbasedfromsystemtypepointofview,andanomalydetectionfromdetectionapproachpointofview.Inaddition,itcandetectmostofnetworkattacks,suchasdenialofservices(DoS),leakage,etc.fromdetectionbehaviorpointofviewandcandetectbothinternalandexternalintrudersfromintrudertypepointofview.GatheringthesefeaturesinoneIDSsystemgiveslotsofstrengthsandadvantagesofthework.Thesystemisimplementedbyusingfieldprogrammablegatearray(FPGA),givingamoreadvantagestothesystem.AC5.0decisiontreeclassifierisusedasinferenceenginetothesystemandgivesahighdetectionratioof99.93%.
简介:WereportthedepositionofNb2O5filmsonunheatedBK-7glasssubstratesusingremoteplasmasputteringsystem.Theremoteplasmageometryallowspseudoseparationofplasmaandtargetbiasparameters,whichofferscompletedepositionratecontrol.Usingappropriateoxygenflowrates,high-densityandlow-lossNb2O5filmsaredepositedwithratesupto0.49nm/s.Lowerdepositionrates(~0.026nm/s)canalsobeobtainedbyworkingatlowtargetcurrentandvoltageandatlowpressure.Nb2O5filmsdepositedatdifferentrateshavetherefractiveindexofabout2.3andtheextinctioncoefficientaslowas6.9×10-5.
简介:WefabricatepolycrystallineCu(In,Ga)Se2(CIGS)filmsolarcellsonpolyimide(PI)substrateattemperatureof450°Cwithsingle-stageprocess,andobtainapoorcrystallizationofCIGSfilmswithseveralsecondaryphasesinit.Forimprovingitfurther,thetwo-stageprocessisadoptedinsteadofthesingle-stageone.AnextraCu-richCIGSlayerwiththethicknessfrom100nmto200nmisgrownonthesubstrate,andthenanotherCu-poorCIGSfilmwiththicknessof1.5-2.0μmisdepositedonit.Withthemodificationoftheevaporationprocess,thegrainsizeofabsorberlayerisincreased,andtheadditionalsecondaryphasesalmostdisappear.Accordingly,theoveralldeviceperformanceisimproved,andtheconversionefficiencyisenhancedbyabout20%.