COUTINHO, I. B. G.; http://lattes.cnpq.br/7402698927487139; COUTINHO, Ianes Barbosa Grécia.
Résumé:
In recentdecades,therehasbeenanexponentialgrowthinthesupplyofwireless
communicationservicesandnewdemandsthatencouragethedevelopmentoftechno-
logies inthisarea.Onesuchtechnologythathasbeendevelopedisrelatedtofrequency
selectivesurfaces,FSSs,withvariousapplicationssuchasreflectors,radomes,efficient
windows,electromagneticallyintelligentwalls,amongothers.Oneofthechallenges
of FSSdesigniswhenawidebandwidthisdesired,especiallywhenitisdesiredthat
the applicationrangeisatlowerfrequenciesbelow2GHz.Oneofthetechniquesthat
can beconsideredtosolvethisproblemistheuseofcascadedFSSs,inwhichmultiple
layersofFSSarecoupledtogetherwithorwithoutasubstratebetweenthem.Inrecent
works,theuseofmatryoshkageometryhasbeenimplemented,withadvantagessuchas
miniaturization, multibandoperationandpolarizationindependence.Thisgeometry
has beenstudiedwithnewtechniquesandapplications,suchasdefectivegroundstruc-
tures, DGS,orcomplementarysplitringresonators,CRSS,butitsusewithcascaded
FSSs hasnotbeendeveloped.Thus,inthisworkitisproposedthedevelopmentof
frequency selectivesurfacesusingthematryoshkageometryandthenegativegeometry
of thecascadedmatryoshkaforbandwidthenhancement,inthefrequencyrangefrom
1.78 GHzto3.82GHz,witha8 8 matrixof24mm2 unitycellsandtwolayersspaced
by12mm,inadditiontoabandwidthof1.2GHzinthefrequencyrangefrom2GHz
to 3.2GHzwithaspacingof4mmbetweenlayers.Numericalresultsareobtained
bymeansofthecommercialsoftwareANSYSDesigner,whichisbasedontheMethod
of Moments,MoM,inadditiontoexperimentalresults,observingagoodagreement
betweenthem.Comparativemeasurementswerecarriedoutfortheanalysisofthe
influence oftheindividualFSSsandtheresponsetodifferentpolarizationsandmea-
surementwindowangularinclinations,confirmingthepossibilityofreachinganultra
wide band,UWB,ofupto2GHzintherangefrom1.78GHzto3.82GHz
