DEVELOPMENTOF FERRITE BASED ABSORBING PAINTS FOR REDUCTION OF EMI /EMC PROBLEMS IN MICROWAVE RANGE

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1 DVLOPMNOF FI BASD ABSOBING PAINS FO DUCION OF MI /MC POBLMS IN MICOWAV ANG M MSHAM, BHAOI SINHA &NAWAL K. AGAWAL, Dpam of lcoics & Compu giig a P.S. MISA Dpam of Mallugical a maials giig Iia Isiu of chology ook 7 7 INDIA Absac:- MI/MC is a poial ha o h wokig of vaious lcical a lcoics vics.o uc i,absobs com as hay ools.his pap pss h hoical aalysis a sig of sigl lay micowav absob usig hxagoal fi i o o uc h lcomagic Ifc (MI poblms a hac lcomagic compaibiliy. A w hoical mol fo a sigl lay absob has b vlop bas o h valuaio of ovall flcio coffici. h compu a xpimal suls fo absopio as a fucio of iff coaig hicksss of absobig lay a i goo agm sablishig h valiiy of h mol.mol is usful fo h vlopm of vaious absobig pais o uc spcific MI poblms. Ky wos:- MI/MC Hxagoal fi,micowav absob, ComplxPmabiliy, aa Absobig Maials. Ioucio lcomagic Ifc (MI is a spcific ki of viomal polluio which is awig mo a mo aio u o xplosiv gowh i h uilizaio of lcic a lcoic vics i iusial, commcial a miliay applicaios. hfo sious lcomagic compaibiliy hav bcom appa.[ ],[]h us of micowav absobs is o appoach o pv MI poblms. I his pap h vlopm of W yp hxagoal fi bas micowav absobig pai as absob i micowav fqucy ag has b ps. Mahmaical mol fo aalysis of sigl lay micowav absob has b ps. Is absopio chaacisics as fucios of vaious paam of is hav b po his aalysis is vy usful fo sig a vlopm of micowav absobig maial. Fi is a vy impoa class of magic maial, mo spcially i is a mal oxi, which coai magic ios aag i such a ma, which poucs spoaous magizaio, a maiais goo ilcic popis. h hxagoal yp fi absob micowav gy by lossy iacio of h magic fil of h wav wih hi iiviual magizaio.h hxagoal fi maials a suiabl as micowav absob u o sigifica valu of pmabiliy (>, high valu of magizaio a plaa a-isoopic bhavio i micowav fqucis.[ ] [ ].SIMULAION OF H MODL h sucu of h sigl lay micowav absob as show i fig., which cosis a h gio, i which PDF ca wih FiPi pffacoy Po ial vsio hp://

2 gio is f spac, gio is absob A gio is mal. Mium( Mium( Mium( F Spac Mal Ici ay Absob flc ay Y Z X Fig. Gomy of h Sigl lay Absob L us cosi a uifom pla wav popagaig i h z icio b ici a a agl θi o h sufac of h absob. A pa of his wav woul b flc back, givig is h pimay flc wav a a pa woul b fac i o h absob iggig a sis of scoay flc wav fom h absobig sufac. h lcic fil isiy a a isac z fom h fis ifac i h absob mia ca b wi as j ( w kz m ( h laiv pmabiliy a pmiiviy of h fi maial giv by ( j ( j a jp.( -j (-ja ( a ( j a a ( j (a j a + a Wh m is h ampliu of h fil i h mium. is h k wav umb i h mium is h f spac wav lgh. ( wh a p a h fcio ix a absopio ix spcivly h isac paam z ca b xpss as PDF ca wih FiPi pffacoy Po ial vsio hp://

3 cos( z ( θ si( si( cos( θ θ θ i si( θ i a Subsiuig quaio ( a ( i o quaio ( h xpssio fo h wav popagaio i h absob mia is giv as ( α + j β m wh α p x β x x [ si ( θ ] i j ϖ ( h fil isiy a a h sco ifac ca ow b xpss (wih im pc suppss as a ( α + j β α a β j ϖ p.( h flc lcic fils,,.. m fom h ou sufac a h oal flc fil is giv by... m ( m ( m ( m ( α ( α + [ ( + + m m m ( + m α β m wh is h asmissio coffici a h fis ifac. I o o mov h pc o polaizaio wihi h absobig mia w impos h coiio giv by[ 8 ] >> physically his assumpio mas ha h wav isi h absob is avlig i a icio,which is omal/a omal o h sufac wih his sicio si ( θ i a hus fom quaio x a hc α p; β. Usig hs w fi wo w vaiabls α a β as wh ( + ( + jp jp flcio loss is giv by l log.(7.dvlopm of Fi Maial & Chaacizaio A sampl of W yp hxagoal fi pow amly [SZ. F. S. M. O.8 ] has b ppa by y aiio a siig pocss. h saig maial w SCO, MCO,SO, ZO a F O. h siig was cai ou a o C fo 8 hous. h fi paicl of PDF ca wih FiPi pffacoy Po ial vsio hp://

4 siz mico was obai by millig. Fish Sub Siv Siz isums cai ou h paicl siz aalysis. h vlop fi pow % by wigh mix i poxy si o fom a micowav absobig pai. h a of fi maial has b masu by op a sho cicui mho.[] h absopio popis fo iff coaig of absobig pai o alumium sh havig iff hickss hav b compu by usig quaio ( & (.h micowav absopio masu by AD mho. [ ]h ilcic cosa of fi maial has b masu by op cicui a sho cicui mho. [ 7 ] O h basis of ilcic cosa ( & of fi maial absopio has b calcula by usig quaio.( 7 ( Micowav Souc ( Isola ( B icioal coupl ( Pow m ( Absob sig Dvic Fig. xpimal S up fo masum of micowav absopio.sul & Discussio:- h vaiaio i complx pmabiliy a complx pmiiviy wih fqucy is show i figu a figu spcivly. h complx pmabiliy plays a impoa ol i ciig h ovall absopio chaacisics of micowav absob. h maximum valu of h imagiay pa of h complx pmabiliy is. is obai a. GHz. which shows ha h soac fqucy of h fi maial is.ghz.h maximum valu of al pa of complx pmabiliy is 8. obai 8a 8.9 GHz. h vaiaio i complx pmiiviy of fi maial wih fqucy is show i fig. fom figu i is obsv ha h pak valu of al pa of complx pmiiviy is. fou a.ghz.h imagiay pa of complx pmiiviy is. a. obai a 8. GHz a GHz spcivly. h compu a xpimal sul of h sigl lay micowav absobig pais fo iff coaig hicksss as show i figu o 7 Fig. shows h hoical a xpimal sul of micowav absopio fo a hickss coaig of.8 mm. I is obsv ha i givs h aow ba chaacisics. h pak valu of absopio 7 B is obai a.8 GHz.I also povi boaba chaacisics wih miimum absopio of. B fom. o. GHz. Fig.shows h absopio chaacisics fo sigl lay micowav absob fo a coaig of. mm, Fom figu i is obsv ha i givs h miimum absopio of.7 B fom 8 o. GHz. I is also isig o o ha PDF ca wih FiPi pffacoy Po ial vsio hp://

5 i povis boaba chaacisic a Ku ba wih miimum absopio of 7.9 B fom. o. GHz. h aus of h xpimal a hoical suls a iical. Fig. shows h absopio cuv fo compu a xpimal sul of sigl lay micowav absob fo a coaig hickss of pai mm. Fom fig. i is obsv ha i povis miimum absopio of B a X ba a givs miimum absopio of.b fom. o. GHz. h pas fo vaiaio of absopio i hoical a xpimal sul a iical..coclusio:- A mahmaical mol fo h hoical aalysis a sig of micowav absob has b vlop. hi cocss has b valia by sig,fabicaio a xpimal sig of a absob o uc aa coss scio a lcomagic ifc i h fqucy ag of 8 o 8 GHz fo a coaig hickss of. mm. I is coclu ha h miimum lvl of absopio ps o coaig hickss of micowav absob.h vaiaios i xpimal a hoical suls a u o ppaaios of fi maial a masum cosais. fcs [] M..Msham, Nawal K. Agawal,Bhaoi Siha a P.S. Misa Dvlopm a Chaacizaio of Hxagoal Fi Bas Micowav Absobig Pais a Ku- Ba I Joual of sach Vol. 7,Nos.,pp.9-,Spmb Ocob [] M Msham, Nawal K Agawal, Bhaoi Siha a P S Misa A ypical Hxagoal fi fom iusial was fo micowav gy absopio a Ku ba Iia Joual of aio & Spac Physics Vol., pp - 9, Augus. []M.B. Ami a J..Jams, chiqus fo h Uilizaio of Hxagoal Fis i aa Absob Pa-I Bao ba Plaa Coaig,h aio a lcoics gis,vol.,pp.9-8,98 [ ] I.Nkov,A.Pkov a V.Kapov, Micowav Absopio i Sc a Co-i Subsiu Ba Hxa Fi pow, I asacio O Magics, Vol. No., pp.8-8, Spmb 99. []S.C.Gupa,N.K.AgawalaChaiaya Kuma M.V. Boa Ba hi Sh Absobs fo S-;C; X-;a Ku Bas Jouals of I Vol. 9,No., pp 97-,May Ju 99. [] Youji Kosuka, Hiaka Yamazaki Fuamal Ivsigaio O a Wakly Magiz Fi Absob I asacio o lcomagic Compaibiliy,Vol.,No.,pp.-,May [7]M..Msham, Nawal K. Agawal Bhaoi Siha, & P.S.Misa,mpiical laioship bw a Fomagic soac Fqucy i Hxagoal Fi Bas Micowav Absobig Pai, Micowav a opical chology ls Vol.,No., pp -, Mach. [8]Chaiaaya Kuma M.V. Dvlopm a Chaacizaio of Micowav Absobs Ph.D. hsis Dpam of lcoics &Compu giig II ook,sp.99 PDF ca wih FiPi pffacoy Po ial vsio hp://

6 COMPLX PMABILIY al Pa Imagiay Pa COMPLX PMIIVIY 8 al Pa Imagiay Pa 8 8 FQUNCY IN GHz FIG. VAIAION IN COMPLX PMABILIY OF W YP FI MAIALS WIH FQUNCY FQUNCY IN GHz FIG. VAIAION IN COMPLX PMIIVIY OF W YP FI MAIAL WIH FQUNCY Compu sul xpima l sul Compu sul xpimal sul ABSOPION IN B 8 ABSOPION IN B 8 8 FQUNCY IN GHz FIG. ABSOPION CUV FO W YP HXAGONAL FI BASD ABSOB FO COAING HICKNSS (.8 mm 8 8 FQUNCY IN GHz FIG ABSOPION CUV FO W YP HXAGONAL FI BASD ABSOB FO COAING HICKNSS OF (. mm ABSOPION IN B Compu sul xpimal sul 8 8 FQUNCY IN GHz FIG 7.ABSOPION CUV FO W YP HXAGONAL FI BASD MICOWAV ABSOB FO COAING HICKNSS ( mm PDF ca wih FiPi pffacoy Po ial vsio hp://