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Smith 2009 - Sources and evolution of mineralising fluids in IOCG systems

The sources and evolution of mineralising ?uids in iron oxide–copper–gold systems,Norrbotten,Sweden:Constraints from Br/Cl ratios and stable Cl isotopes of ?uid inclusion

leachates

S.A.Gleeson a,*,M.P.Smith b

Department of Earth &Atmospheric Sciences,University of Alberta,Edmonton,Alta.,Canada T6G 2E3b

School of the Environment,University of Brighton,Cockcroft Building,Lewes Road,Brighton BN24GJ,UK

Received 25February 2009;accepted in revised form 11June 2009;available online 16June 2009

Abstract

We have analysed the halogen concentrations and chlorine stable isotope composition of ?uid inclusion leachates from three spatially associated Fe-oxide ±Cu ±Au mineralising systems in Norrbotten,Sweden.Fluid inclusions in late-stage veins in Fe-oxide–apatite deposits contain saline brines and have a wide range of Br/Cl molar ratios,from 0.2to 1.1?10à3and d 37Cl values from à3.1&to à1.0&.Leachates from saline ?uid inclusions from the Greenstone and Porphyry hosted Cu–Au prospects have Br/Cl ratios that range from 0.2to 0.5?10à3and d 37Cl values from à5.6&to à1.3&.Finally,the Cu–Au deposits hosted by the Nautanen Deformation Zone (NDZ)have Br/Cl molar ratios from 0.4to 1.1?10à3and d 37Cl values that range from à2.4&to +0.5&,although the bulk of the data fall within 0&±0.5&.

The Br/Cl ratios of leachates are consistent with the derivation of salinity from magmatic sources or from the dissolution of halite.Most of the isotopic data from the Fe-oxide–apatite and Greenstone deposits are consistent with a mantle derived source of the chlorine,with the exception of the four samples with the most negative values.The origin of the low d 37Cl values in these samples is unknown but we suggest that there may have been some modi?cation of the Cl-isotope signature due to fractionation between the mineralising ?uids and Cl-rich silicate assemblages found in the alteration haloes around the depos-its.If such a process has occurred then a modi?ed crustal source of the chlorine for all the samples cannot be ruled out although the amount of fractionation necessary to generate the low d 37Cl values would be signi?cantly larger.

The source of Cl in the NDZ deposits has a crustal signature,which suggests the Cl in this system may be derived from (meta-)evaporites or from input from crustal melts such as granitic pegmatites of the Lina Suite.ó2009Elsevier Ltd.All rights reserved.

1.INTRODUCTION

The iron oxide–copper–gold (IOCG)deposit class has attracted much attention in recent years,both in terms of academic research and exploration activity.The deposits are characterised by Cu-sulphides ±Au hydrothermal ores with abundant magnetite or hematite and occur in rocks ranging from Late Archaen to the Cenozoic in age

(Williams et al.,2005).IOCG deposits do not have a clear spatial association with igneous rocks,have disputed tec-tonic settings and variable geological characteristics.Also,the sources of the major components in many of the depos-its are unknown.However,all the deposit types are com-monly found in sequences which have undergone large scale sodic alteration and contain Cl-rich silicate minerals such as scapolite,biotite and amphiboles.

The relationship between Fe-oxide–apatite (e.g.Kiruna-type)and the IOCG deposits has also been a contentious point in the literature.The common spatial relationship

Corresponding author.

E-mail address:sgleeson@ualberta.ca (S.A.Gleeson).

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Geochimica et Cosmochimica Acta 73(2009)

5658–5672

of these deposit types(and in some cases their direct super-position)has lead to suggestions that they are part of the same deposit class or that there are genetic links between the two(Hitzman et al.,1992).This is supported by early stage magnetite alteration in many IOCG deposits(e.g. Smith et al.,2007),the late-stage occurrence of pyrite,chal-copyrite and gold in and near massive magnetite deposits, and the common features in alteration associated with both deposit types(Sillitoe,2003).However,recent work has highlighted a signi?cant di?erence in timing of the two de-posit types in some areas(Hitzman,2000)indicating that a direct genetic link between the two may not exist.

One of main di?culties in constructing a genetic model for these deposits is determining the?uid sources at di?er-ent stages of mineralisation,in part due to the modi?cation of?uid stable isotope characteristics by water–rock interac-tion in the deposit class as a whole(Haynes,2000).A num-ber of di?erent genetic models have been suggested for the deposit class including(1)a magmatic source for the miner-alising?uids(e.g.Pollard,2000,2006);(2)a magmatic source that has been modi?ed by large scale?uid circula-tion forming the regional sodic alteration and adding met-als to the mineralising?uid(e.g.Oliver et al.,2004);(3)a non-magmatic,evaporite or near-surface continental brine derived origin for the?uids(Barton and Johnson,1996, 2000;Xavier et al.,2008);(4)a metamorphic source for the?uids(Fisher and Kendrick,2008);(5)a mixed mag-matic–basinal brine origin(Chiaradia et al.,2006;Baker et al.,2008;Kendrick et al.,2008).Metamorphism of evap-orites has also been invoked to explain the regional distri-bution of sodic alteration in the Kiruna district, Norrbotten,Sweden although no Fennoscandian evaporitic sediments are preserved(Frietsch et al.,1997).However,it has been suggested that some occurrences of apparently stratigraphically restricted scapolite in the Greenstone group have are related to former evaporite beds(Martins-son,1997).It is now recognised that the class represents a diverse group with the potential for a wide range of poten-tial?uid sources(Williams et al.,2005).

In Norrbotten both deposits hosted by the Greenstone and Porphyry Group metavolcanic rocks,and deposits hosted regionally signi?cant deformation zones such as the Nautanen Deformation Zone(NDZ),have been pro-posed to belong to the IOCG class.They are linked by the ubiquitous presence of magnetite as an alteration phase, and the common occurrence of scapolite in alteration assemblages,despite other variations.It is,therefore,perti-nent to examine the deposits together in order to investigate the range of brine sources operating over time in the area, and in particular to investigate if common sources periodi-cally supplied?uid accounting for the geochemical similar-ities in the deposit types.In this study,we examine the Cl and Br concentrations and,using an on-line mass spectro-metric technique,the stable chlorine isotopic composition of dilute leachates(>20ppm total chloride)derived from microthermometrically well characterised vein quartz sam-ples.We compare the source of Cl in Kiruna-type Fe-oxide–apatite and IOGC deposits of the Norrbotten dis-trict,Sweden and provide new constraints on the?uid source and water–rock interaction history in deposits and prospects in this important metallogenic province.Bulk leachates are currently the only way to examine the chlorine stable isotope chemistry of inclusion?uids.

2.BACKGROUND GEOLOGY

The major iron ore province of northern Sweden is lo-cated in Norrbotten County and is mainly hosted by Palae-oproterozoic rocks(see reviews by Carlon(2000)and Bergman et al.(2001)).These deposits are mainly Karelian (2.5–2.0Ga)and Svecofennian(1.9–1.88Ga)in age(Fig.1) and are preserved in deformed and metamorphosed belts, intruded by a range of granitoid plutons.Metamorphic conditions peaked at upper greenschist or lower amphibo-lite facies during the Svecofennian Orogeny from1.9to 1.8Ga(Skio¨ld,1987).A detailed lithostratigraphy of these rocks has been proposed by Martinsson(1997).The Green-stone Group(>1.9Ga),consisting of mainly tholeiitic(Ek-dahl,1993)to komatiitic(Martinsson,1997)volcanic rocks overlies Archaean basement.These are overlain?rst by the Middle Sediment Group(Witschard,1984),and then by the Porphyry Group,which consists of volcanic and sub-volca-nic rocks,subdivided in the Kiruna area into the domi-nantly andesitic Porphyrite Group,and the syenitic and quartz-syenitic Kiruna Porphyries which host the Kiruna-vaara magnetite–apatite deposit.In view of their proximity to the Kirunaavaara deposits the Kiruna porphyries may have acquired their syenitic character via alkali metamor-phism,and it is likely that the original volcanic rocks were calc-alkaline in character.The Haparanda and Perthite–monzonite calc-alkaline and alkali-calcic granite suites in-truded these rocks between1.9and1.8Ga(Skio¨ld,1987) followed by the Lina Suite granitoids at around1.79Ga (Skio¨ld,1987;Bergman et al.,2001).The youngest plutonic rocks in the area are TIB2granitoids,at around1.71Ga in age,exposed at the Swedish–Norwegian border(Romer et al.,1994).The area is cross-cut by a series of large scale shear systems including the NDZ,which is notable for its association with mineralisation.It is a NNW trending tec-tonic structure where strongly schistose or mylonitic rocks occur in several high strain branches in a zone up to3km wide(Martinsson and Wanhainen,2004).

The Palaeoproterozoic rocks of Norrbotten area are af-fected by scapolite and albite alteration at both the regional and deposit scale,where they are associated with both iron oxide and Cu–(Au)mineralisation(Frietsch et al.,1997). Samples for this study were taken from three groups of mineralising systems;late-stage quartz veins cutting Fe-oxide–apatite deposits and associated alteration;minerali-sation-related quartz veins from Cu–(Au)prospects hosted by the Greenstone and Porphyry Groups,and mineralisa-tion-related quartz veins from the heavily deformed meta-volcanic rocks of the NDZ.

Data on the timing of the scapolization of the area are limited,but Smith et al.(in press)report a U–Pb titanite age of1903±8Ma for titanite in a scapolite altered diorite at Nunasvaara.The Fe-oxide–apatite deposit at Kiirunava-ara has been dated as forming between1884±6and 1875±9Ma(Romer et al.,1994),whilst Storey et al. (2007)showed that titanite from Luossavaara had distinct

Chlorine isotopes in iron oxide–copper–gold deposits Sweden5659

cores with ages of ca.2050Ma,and rims with ages of 1870±24Ma,indicating that the Fe deposits are truly epi-genetic.The timing of Cu-deposition has been addressed by Billstro ¨m and Martinsson (2000),who identi?ed two main periods of IOCG mineralisation of 1850–1880Ma,and from 1750to 1800Ma.The early period is supported by re-cent work on the Rakkurija ¨rvi prospect (Smith et al.,2007),where Re-Os analyses of molybdenite give ages of 1853±6Ma and 1862±6Ma,whilst the later period is associated with the major deformation zones at Nautanen and elsewhere.The later period also corresponds to a peri-od of metamorphism of pre-existing deposits identi?ed at Malmberget (initial mineralisation ages of 1920±23Ma with lead loss and re-equilibration of titanite down to 1708±20Ma,Storey et al.,2007),in titanite from Cu-prospects (Smith et al.,in press),and in secondary modi?-cation and sulphide mineralisation at Kiirunavaara (Cli?and Rickard,1992;Romer et al.,1994).The data available at present are consistent with an overlap in time between re-gion Na-alteration and Fe-oxide–apatite mineralisation,with the initial period of Cu mineralisation overlapping with,or slightly postdating the late stages of Fe-oxide min-eralisation.They indicate periods of both Fe-oxide and in-ital Cu mineralisation overlap with the intrusion period of the Haparanda and Perthite monazite suite granitoids and

with the initial period of Svecofennian metamorphism,whilst the later group of Cu deposits overlap with the intru-sion of the Lina Suite granitoids and a later period of meta-morphism (Bergman et al.,2001;Martinsson,2004).2.1.Fe-oxide–apatite deposits

The Fe-oxide–apatite bodies are typi?ed by the Kiruna-vaara–Luossavaara magnetite dominated bodies,and the Per Geiger ores which contain both hematite and magnetite (Geijer,1910,1931;see Martinsson,2004for a recent re-view).The deposits are accompanied by sodic and potassic alteration (albite–K–feldspar–biotite),which in some in-stances includes scapolite.Samples from the Kirunava-ara–Luossavaara deposit are either from quartz–carbonate–(magnetite–titanite)veins which cut the ore body,or one sample from the summit of Kirunavaara which consists of a quartz–calcite–actinolite–hematite–titanite vein which forms a late-stage fracture ?ll in the ma-trix of the magnetite-cemented,Na–K altered metavolcanic breccia exposed in the hanging wall of the ore body.A quartz–albite–tourmaline vein was sampled cutting the main magnetite–apatite body at Mertainen.Samples from the magnetite–hematite–apatite bodies of the Per Geiger ores are taken from the Nuktus and Henry bodies,and

in-

Fig.1.Location map of the study area with regional geology after Bergman et al.(2001).Samples were collected from Fe-oxide–apatite deposits,Greenstone and Porphyry-hosted Cu–Au deposits and Cu–Au deposits associated with the Nautanen Deformation Zone.

5660S.A.Gleeson,M.P.Smith /Geochimica et Cosmochimica Acta 73(2009)5658–5672

clude quartz–chalcopyrite or quartz–hematite veins cutting the oxide ore bodies or the surrounding rock.

2.2.Porphyry and Greenstone hosted Cu–Au deposits

Quartz vein samples related to Cu–Au mineralisation were taken from the Pahtohavare(Lindblom et al.,1996; Martinsson,2004),Gruvberget(Martinsson and Virkkunen, 2004),Kiskamavaara(Martinsson and Wanhainen,2000) and Kallosalmi(Wa¨gman and Ohlsson,2000)deposits and prospects.Both Pahtohavare and Kallosalmi are Green-stone group hosted mineralisation,and Pahtohavare was mined from1990to1997.The mineralisation in both cases is developed in basaltic metavolcanics and metasedimentary schists a?ected by sodic alteration including both scapolite and albite,potassic alteration and carbonate metasomatism (Martinsson,2004).At Kiskamavaara a quartz vein was sampled from hematite cemented K-altered metavolcanic breccia.At Gruvberget Cu mineralisation directly over-prints a magnetite–hematite–apatite body associated with intense scapolite–albite and later potassic alteration.The Cu mineralisation is associated with the potassic(K–feld-spar)alteration(Martinsson and Virkkunen,2004).

2.3.Nautanen Deformation Zone

Quartz veins associated with Cu mineralisation where also taken from sites associated with the NDZ.The miner-alisation is associated with scapolite,tourmaline,sericite and K–feldspar–epidote alteration,alongside the develop-ment of metasomatic garnet,and is hosted within a major shear zone(Martinsson and Wanhainen,2004).The sam-ples come from both the main Nautanen prospect,and from the Ferrum vein hosted Cu–Au prospect on the mar-gins of the main deformation zone.

3.ANALYTICAL TECHNIQUES

Petrographic and microthermometric studies were car-ried out on doubly-polished?uid inclusion wafers for all sample veins.Microthermometric data was collected using a Linkam THMSG600heating and freezing stage which was calibrated atà56.6,0,and10°C using synthetic?uid inclusion standards and distilled water,and at high temper-atures using a range of pure solids.Reported temperature measurements have a precision of±0.2°C on cooling runs, and for heating runs within±1°C.

Quartz veins were isolated from the host rock using a small rock saw,coarsely crushed and hand-picked for pur-ity,and then crushed and leached using the technique de-scribed in Gleeson and Turner(2007).Leachate samples were analysed for anions(including Clàand Brà)using a Dionex DX600ion chromatograph?tted with an AS-14 analytical column.The detection limit for the anions was 0.008ppm.Analyses of standard solutions and replicate analyses of leachates were reproducible within5%.

The same?uid inclusion leachate analysed by ion chro-matography was used for Cl-isotope analysis.Chloride in the leachate was isolated by precipitation of silver chloride salt(AgCl)as described by Long et al.(1993)and Wassenaar and Koehler(2004).Filters were placed inside foil wrapped10ml glass serum vials to prevent photo-disso-ciation(Long et al.,1993).Quantitative conversion of AgCl to CH3Cl gas was carried out at the Stable Isotope Hydrol-ogy and Ecology Laboratory of Environment Canada in Saskatoon,Saskatchewan using the Iodomethane(CH3I) reaction as described by Wassenaar and Koehler(2004). The d37Cl values were obtained using a multicollector GV Instruments Isoprime TM IRMS.Multiple injections of 100%CH3Cl were repeatable within(±SD)0.06&for d37Cl analyses(Wassenaar and Koehler,2004).To correct the CH3Cl d37Cl values relative to the Standard Mean Ocean Chloride(SMOC)reference(Kaufmann et al., 1984),standards were prepared using200l L of Ocean Sci-enti?c Internal Stock Atlantic Seawater and G-10953sea-water(internal east coast seawater standard).

4.RESULTS

4.1.Fluid inclusion petrography and microthermometry

The Palaeoproterozoic rocks of the northern Norrbotten district have typically reached lower greenschist facies meta-morphic conditions syn-to post-mineralisation(Bergman et al.,2001),and vein quartz commonly shows some evi-dence for deformation and recrystallisation along grain mar-gins.As a result careful characterisation was necessary in order to ensure that inclusions are related to the mineralising event.All the?uid inclusions analysed were classi?ed according to their room temperature phase assemblage (see Table1and Figs.2and3)and the results of the?uid inclusion microthermometric study are summarised in Table 1.The full details of all heating–freezing experiments will be the subject of a future paper.Many of the observations made here are in agreement with previous work by Broman and Martinsson(2000)and Lindblom et al.(1996).Weight% NaCl equivalent salinities were calculated from halite disso-lution temperatures using the equation of Sterner et al. (1988)for halite bearing inclusions,from the ice melting temperature using the equation of Bodnar(1993)for aque-ous inclusions,and from clatherate melting in the Q2assem-blage using the equation of Diamond(1992).

The late-stage quartz veins from the Fe-oxide–apatite deposits contain a large number of?uid inclusions,and the paragenetic setting of inclusions is sometimes di?cult to determine.However,along with inclusions trapped on annealed trails,inclusions of consistent microthermometric properties sit in unequivocally primary settings,typically trapped in arrays that parallel growth zones or isolated in grain cores(Fig.2A and B).Hence,we interpret the mic-rothermometric properties of these inclusions to represent the?uid present during and immediately post-quartz vein formation.The inclusions are dominantly halite saturated (Fig.3A)with a salinity of30–40wt.%NaCl eq.and homogenisation temperatures(T h)in the range of100–150°C.The exception to this is a single sample from the Mertainen magnetite body which had salinities in the range 40–60wt.%NaCl eq.The sample from the Henry Fe-oxide–apatite body is also notable in that halite-bearing inclusions showed a double meniscus and a small amount of CO2

Chlorine isotopes in iron oxide–copper–gold deposits Sweden5661

within the inclusion,and was the only occurrence of a min-or aqueous–carbonic inclusion population in these veins.

In Pahtohavare and other relatively undeformed IOCG deposits(Fig.2C and D),the inclusions are likewise trapped in growth zones with some secondary trails,which are dominated by CO2-rich inclusions(Lindblom et al., 1996).In both deposit types previous workers have also identi?ed inclusions as primary or pseudosecondary in ori-gin(Lindblom et al.,1996;Broman and Martinsson,2000; Harlov et al.,2002).The?uids associated with quartz veins from Greenstone and Porphyry hosted Cu–(Au)deposits and prospects,ranged from much higher salinities(around 50–60wt.%NaCl eq.)at Pahtohavare and Kallosalmi and one example from Gruvberget,to those comparable with the late-stage veins associated with the Fe-oxide bodies at Kiskamavaara and an additional sample from Gruvberget (Fig.3B–D).In a number of cases a secondary carbonic inclusion?uid inclusion population occurred composed of virtually pure CO2(all inclusions had solid CO2melting atà56.6±0.2°C).

At Nautanen and other NDZ related deposits all the inclusions analysed are trapped in annealed fractures.High salinity inclusions are similar to those noted as primary in the Aitik deposit by Wanhainen et al.(2003),who also noted that such inclusions are associated with solid inclu-sions of chalcopyrite,and inclusions with daughter or trapped chalcopyrite grains.

The inclusion assemblage from deposits associated with the NDZ includes coexisting inclusions containing aqueous liquid,a halite daughter and a vapour phase(Lw+Sh+V; Fig.3E)and some contained a liquid carbonic phase also (Lw+Lc+V and Lc+V:Fig.3F).In some instances

Table1

Summary of the microthermometric data.

N Inclusion types Para.XCO2Salinity Th

Mean Min Max Mean Min Max Mean Min Max Magnetite–(Hematite)–apatite

KR228Lw+Sh+V P/PS/S ND33.231.436.610294117 L4.128Lw+Sh+V P/PS/S ND36.533.441.2122102156 03HENRY0416Lw+Sh(+Lc)+V P/PS/S0.020.010.0334.733.337.911896165 03HENRY0410Lw+Lc+V PS/S0.040.030.0621.421.421.5212189242 N128Lw+Sh+V P/PS/S ND33.331.535.3150106202 N2.224Lw+Sh+V P/PS/S ND34.932.939.410381124 N2.521Lw+Sh+V P/PS/S ND35.331.538.511087131 MER225Lw+nS+V PS/S ND52.040.259.5145105164 Greenstone-and Porphyry-hosted Cu

KALL9100259.53m15Lw+nS+V P/PS ND49.132.761.1139111154 11Lw+Sh+V PS/S ND32.231.632.910190107

6Lw+V PS/S ND24.223.924.8120110138 PAH8821721.20m16Lw+nS+V P/PS/S ND53.646.357.4119102132 PAH85117152.14m19Lw+nS+V P/PS/S ND49.041.457.0161122193

Lc+V PS/S Lc+V inclusions(S)

P1123Lw+nS+V P/PS/S ND42.034.149.1137124164 K227Lw+Sh+V P/PS/S ND33.531.137.2118103150 G622Lw+nS+V P/PS ND42.838.148.811997159 8Lw+Sh+V PS/S ND41.140.541.6128120134 G5.116Lw+nS+V P/PS ND34.533.237.1130120138

Lc+V PS/S Lc+V inclusions(S)

Nautanen Deformation Zone(NDZ)-hosted Cu

FERR6920572.75m3Lw+Sh+V PS/S ND31.328.133.9141135147 18Lw+V PS/S ND21.718.624.0152130214 NAU77006210.4m5Lw+Lc+V PS/S0.180.170.29.1 3.712.4263243300 17Lw+Sh+V PS/S ND34.831.541.021*******

22Lw+V PS/S ND19.412.028.3144106203

Lc+V PS/S Lc+V inclusions(S)

NAU77006281.7m18Lw+Sh+V PS/S ND33.231.335.0133112183 11Lw+Sh+V PS/S ND28.927.829.9140117143

Lc+V PS/S Lc+V inclusions(S)

03NAU0220Lw+Sh+V PS/S ND33.230.235.4146132183

Lc+V PS/S Lc+V inclusions(S)

NAU83009110.90m30Lw+Sh+V PS/S ND29.326.232.2158113206 3Lw+Lc+V PS/S0.230.190.2910.3 6.712.9

Lc+V PS/S Lc+V inclusions(S)269250281 N,number of inclusions analysed;Lw,liquid water;Sh,halite;V,vapour;Lc,carbonic liquid;nS,multiple solids;P,primary;PS, pseudosecondary;S,secondary;XCO2,Mole fraction CO2calculated from estimated phase volumes;T h,Liquid–vapour homogenisation temperature;ND,not determined.

5662S.A.Gleeson,M.P.Smith/Geochimica et Cosmochimica Acta73(2009)5658–5672

these are preserved along the same secondary ?uid inclusion trails.Lw +Sh +V inclusions from some veins at Nauta-nen had similar salinities and homogenisation temperatures to those from the Fe-oxide and Cu–Au deposits already dis-cussed.At Nautanen,complex inclusion assemblages were hosted on secondary trails,suggesting phase separation oc-curred in the system.Salinities varied from $12–18wt.%NaCl eq.for Lw +Lc +V inclusions to $29wt.%NaCl eq.for halite bearing inclusions.Total homogenisation tem-peratures for Lw +Lc +V inclusions were typically around 250–300°C,whilst L àV homogenisation for halite bear-ing inclusions was around 100–120°C.At both Nautanen and Ferrum a further assemblage of brines was observed.These are reported with NaCl-equivalent salinities in Table 1,but their freezing behaviour was consistent with a Ca-rich brine,with Ca constituting up to 50%of the cations present (Oakes et al.,1990).

4.1.1.Suitability of the samples for bulk extraction

All the samples from Fe-oxide–apatite bodies contained halite-bearing ?uid inclusions at room temperature (Table 1),with the exception of a chalcopyrite-bearing quartz vein from the Henry deposit,which also contained inclusions of an aqueous–carbonic ?uid.The samples from the Green-stone and Porphyry-hosted Cu mineralisation were also dominated by single populations of inclusions with multiple daughter solids (at Pahtohavare identi?ed as including syl-vite,calcite,hematite,graphite and others see Lindblom et al.,1996),including halite in all cases.Lower salinity sec-ondary inclusion populations occurred in samples from Kallosalmi,and secondary CO 2-rich inclusions were a fea-ture in some samples,however,these will not a?ect the overall Cl budget in the sample.These samples are,there-fore,ideally suited to crush–leach analytical techniques in-tended to determine the composition of the high salinity inclusions.

The samples from the NDZ-related deposits typically showed more complex inclusion populations.Samples 03NAU02and FERR6920572.75m were both dominated by a single ?uid inclusion population –halite-bearing inclu-sions at Nautanen and aqueous-liquid plus vapour at Fer-rum,and so are directly suitable for crush–leach analysis.Other samples from Nautanen showed complex,multistage inclusion assemblages,in most case with evidence for

co-

Fig.2.Evidence for primary origin of inclusions.(A)Quartz grain from sample L4.1.Halite-bearing aqueous inclusions occur in growth zone parallel bands and isolated settings (I and II)and in secondary trails (III).(B)Quartz grain from sample N2.The grain is nucleated on magnetite wall rock,and shows lath shaped magnetite growth along a crystal face.Primary bands of halite-bearing ?uid inclusions (II–IV)and solid magnetite inclusions are parallel to the growth face.The crystal is also cut by secondary trails of halite bearing inclusions (I).(c)Quartz grain from sample PAH85117152.14m.Vein margin parallel bands of ?uid inclusions are overgrown by relatively inclusion free quartz with actinolite inclusions.(D)Quartz grain from sample KAL9100259.53m.The core of the grain shows a high inclusion density with occasional large inclusions (I)and is overgrown by an inclusion free rim.In all cases the quartz is cut by trails of secondary inclusions.The scale bar in photomicrographs of ?uid inclusions is 10mm unless otherwise shown.

Chlorine isotopes in iron oxide–copper–gold deposits Sweden 5663

existing halite plus liquid plus vapour (Lw +Sh +V)and aqueous–carbonic inclusions (Lw +Lc +V)indicative of aqueous–carbonic phase separation.In these cases the leachate will be a mixture of material from all inclusion gen-erations,but the halogen signature will be dominated by the most saline populations –typically the Lw +Sh +V inclu-sions which are part of the unmixed aqueous–carbonic assemblage.

4.2.Halogens and d 37Cl values

Halite bearing ?uid inclusions in the Fe-oxide–apatite deposits have a range in Br/Cl molar ratios,from 0.2to 1.1?10à3,although the bulk of the data span the range 0.2–0.3?10à3(Table 2;Fig.4).These samples have d 37Cl values from à3.1&to à1.0&.Leachates with salin-ities dominated by ultra saline ?uid inclusions from the Greenstone and Porphyry hosted Cu–Au prospects have Br/Cl ratios that range from 0.2to 0.5?10à3and d 37Cl values from à5.6&to à1.3&(Table 2;Fig.4).The latter value is the lowest d 37Cl value obtained from ?uid inclusion leachates to our knowledge.Finally,the NDZ hosted Cu–Au deposits have Br/Cl molar ratios that range from 0.4to 1.1?10à3and have signi?cantly di?erent d 37Cl values that range from +0.5&to à2.4&,although the bulk of the data fall within ±0.5&of 0&(Table 2).

5.DISCUSSION

The aim of this study was to compare and contrast the source of Cl in the three spatially related mineralizing sys-tems.The Br/Cl ratios of sedimentary brines have been successfully used to distinguish between Br-rich ?uids gen-erated by evaporative concentration of seawater and Cl-rich ?uids derived from the dissolution of halite (e.g.Kes-ler et al.,1995).The Br/Cl ratios of metamorphic ?uids can vary widely but seem to be strongly controlled by the original source of the salinity rather than metamorphic grade (Yardley and Graham,2002).The Br/Cl composi-tion of magmatic ?uids is less well constrained,mostly due a paucity of data on the behaviour of Br during the exsolution of a hydrothermal ?uid from a crystallizing melt and subsequent processes such as phase separation (see discussion in Nahnybida et al.(in press)).However,previous studies on porphyry deposits suggest that many magmatic systems are associated with hydrothermal ?uids with molar Br/Cl ratios in the range 0.5to 2.0?10à3(Ir-win and Roedder,1995;Bo ¨hlke and Irwin 1992;Banks et al.,2000a,b;Kendrick et al.,2001;Nahnybida et al.,in press ).

There are two main reservoirs of Cl on the planet.The crustal chlorine reservoir is dominated by the oceans,with isotopic values around 0&in the Phanerozoic (Kaufmann et al.,1984;Godon et al.,2004a ).Analyses of Phanerozoic evaporites yield d 37Cl data with a total range of 0&±0.9&(Eastoe et al.,2007).Likewise shield brines and most formation waters also have compositions within this range (e.g.Eastoe et al.,1999,2001;Shouakar-Stash et al.,2007),although there is one study of formation waters in the North Sea that yield data down to –4.7&(Ziegler et al.,2001).Sharp et al.(2007)report d 37Cl val-ues from Precambrian cherts in the range of à3.16&to +1.04&with the bulk of the data falling within 1&of 0.The Cl in these samples is presumed to be hosted in sal-ine ?uid inclusions of unknown age.If these samples truly are representative of Precambrian seawater,this may sug-gest that the Cl isotopic composition of Precambrian oceans were not dissimilar to those of the

Phanerozoic.

Fig.3.Representative examples of ?uid inclusion types in vein quartz samples.(A)Lw +Sh +V inclusion,Kiirunavaara.(B)Lw +Sh +V inclusion,Nuktus.(C)Lw +nS +V inclusion,Gruvberget.Daughter solids include halite and a carbonate phase.(D)Lw +nS +V inclusions,Pahtohavare.Daughter solids include halite and a carbonate phase.(E)Lw +Sh +V inclusion,Nautanen.(F)Lw +Lc +V (carbonic phase dominated)inclusions,Nautanen.

5664S.A.Gleeson,M.P.Smith /Geochimica et Cosmochimica Acta 73(2009)5658–5672

Although there is clearly some variability in the reservoir which is not well understood,since the crustal Cl budget is so strongly dominated by the oceans and evaporites,the isotopic reservoir can be considered to have d 37Cl val-ues of 0&±0.9&(on the basis of data published by Eas-toe et al.(2007)).

The composition of the mantle has been much more dif-?cult to constrain due to the di?culties of analysing Cl bound in mineral phases.An early study using pyrohydro-lysis and thermal ionisation mass spectrometry of some mid-ocean ridge basalts suggested the mantle had a chlorine isotopic value of +4.7&(Magenheim et al.,1995).The data from this study,and subsequent studies using the same technique,have recently been disputed (Sharp et al.,2007;Bonifacie et al.,2007,2008a ).Using a gas-source mass spec-trometer Sharp et al.,2007published data from twelve MORB glasses and three samples of mantle derived conti-nental material and suggested a revised range of mantle val-ues between à1.04&and 0.37&(with an average of à0.1&).They also published data form kimberlitic halite and carbonatites with values close to 0&.Using the same analytical technique Bonifacie et al.(2007,2008a)reported analyses of a larger dataset of MORB samples and sug-gested that the mantle has values of 6à1.6&.A more re-cent secondary ion mass spectrometry study of MORB glasses and melt inclusions produced d 37Cl values that over-lap those of the Bonifacie et al.(2008a)study and extend the range down to à3.0&(Layne et al.,2009).Although the study of the chlorine isotopic composition of the mantle is in its infancy there is clearly emerging support for an iso-topically heterogeneous mantle with values that overlap with the crustal reservoir at the upper end but may extend to more negative values.

5.1.Fe-oxide–apatite and Greenstone and Porphyry hosted Cu deposits

The Fe-oxide–apatite deposits have ?uid inclusion leach-ates with a wide range in Br/Cl ratios with negative d 37Cl values.The Br/Cl ratios of the leachates are comparable to values that are associated with magmatic–hydrothermal ?uids and also ?uids that have acquired their salinities by dissolving halite.One sample is has a d 37Cl value that over-laps the values that might be expected for either seawater or an evaporitic source of Cl in the system,but most of the data have isotopic compositions that are consistent with a mantle derived source of the chlorine as de?ned in the re-cent study by Layne et al.(2009).

The halogen ratios in the Greenstone and Porphyry hosted Cu–(Au)deposits have a narrow range,between 0.2and 0.5?10à3(Fig.4)and these data can be inter-preted as representing a magmatic–hydrothermal ?uid (e.g.Nahnybida et al.,in press ).These samples have a wide range in d 37Cl values and there is some overlap with the ?u-ids from the Fe-oxide–apatite in that the upper values of this datasets coincides with the suggested mantle values.Again,this is supportive of a mantle source of the Cl in the Cu deposits.Arc-related granitoids of the Haparanda and Perthite–Monzonite Suites are exposed throughout the area (Martinsson,2004),and signi?cantly overlap in time with the inferred period of Fe-oxide–apatite and IOCG mineralisation (Bergman et al.,2001)and it is possi-ble that these intrusions may be adding Cl to the mineraliz-ing systems.This supports the general genetic hypothesis for IOCG deposits of Pollard (2006)that intrusions are likely to be the source for the metals,but high con?ning pressures prevent hydraulic brecciation in intrusive envi-ronments,and result in the channelling of ?uids onto large scale tectonic structures resulting in extensive zones of ?uid rock interaction,and the development of deposits distal from potential ?uid-source intrusions.

However,there are a four isotopic data in both deposit types that trend to much lower values (Fig.4)and a second,isotopically distinct source of Cl or a process that fraction-ates the Cl isotopes must be invoked to explain these values.5.1.1.Mixing with,or assimilation of,a low d 37Cl source versus fractionation in the hydrothermal systems

Other than the mantle reservoir,and a single example of formation water ?uids,there are not many other sources of materials with highly negative isotopic compositions.Ion ?ltration over long ?ow paths have also been cited as a pos-sible mechanism for the production of low d 37Cl values in basinal sediments and accretionary prism ?uids (Eastoe et al.,2001;Godon et al.,2004b ),but this mechanism in-volves the preferential repulsion of 35Cl by negatively charged clay surfaces,and may not be as e?ective in the mica and amphibole dominated metamorphic rocks of the Norrbotten area.

The most negative d 37Cl values have been found in sub-duction zone pore ?uids and include data that range from à7.8to +1.8(Ransom et al.,1995;Spivack et al.,2002;Wei et al.,2008).The lowest chlorine isotopic values docu-mented in ?uids come from the Nankai Trough (Wei et

al.,

Fig. 4.A plot of the d 37Cl values of ?uid inclusion leachates against Br/Cl molar ratios.The dashed box indicates the compo-sition of the crustal Cl reservoir (Eastoe et al.,2007)and the shaded box is a range of potential mantle values as outlined by Layne et al.(2009),Bonifacie et al.(2008a),Sharp et al.,2007;Johnson et al.,2000and Jambon et al.,1995.

5666S.A.Gleeson,M.P.Smith /Geochimica et Cosmochimica Acta 73(2009)5658–5672

2008);these samples have isotopic compositions that range fromà7.8&to+0.3&and corresponding Br/Cl molar ra-tios that are higher than the seawater value of1.5?10à3 with an upper limit of2.7?10à3.These authors suggest that the?uids gain their Br/Cl compositions during the for-mation of hydrous minerals at depth(P250°C)that ex-clude Br from their structures(resulting in an increase in the Br/Cl ratio of co-existing?uids)and an associated frac-tionation of the Cl isotopes.However,there is no experi-mental data to support this hypothesis at this time.

The Svecokarelian orogeny has been modeled as the accretion of at least two arc systems onto an Archaean con-tinent(Nironen,1997;Weihed et al.,2005).There is some potential for the generation of pore?uids with negative iso-topic compositions in accretionary prisms in such an envi-ronment.However,the Fe-oxide–apatite and the Cu–Au deposits are thought to have formed at depths of at least 8–10km(Lindblom et al.,1996)and transporting an(isoto-pically)isolated Cl source into the mineralizing system is problematic.Equally,all the?uids analysed here have Br/ Cl molar ratios that are less then seawater and we do not observe an associated Br enrichment with the more negative isotopic end-member suggesting that simple mixing(or assimilation)of the type of?uids described by Wei et al. (2008)is not the most likely resolution.This is supported by the range in?uid inclusion microthermometric salinity data,which suggest that mixing could have occurred but both?uid end-members would have to be brines.

One of the characteristic features of both the Fe-oxide–apatite and Greenstone and Porphyry hosted Cu deposits is the presence of a Cl-rich alteration assemblage.This is most notably developed as regional scapolite(dominated by the marialite component)and albite alteration(Frietsch et al., 1997),but also as high Cl-biotite and more proximal scap-olite alteration around deposits.There are no experimental data on the fractionation of the isotopes between Cl bearing silicate minerals and?uids particularly at the temperatures of the systems discussed here.Chlorine isotope equilibrium fractionation was modeled using a numerical approach by Schauble et al.(2003)who calculated that silicates should have37Cl/35Cl ratios that are2–3&higher that co-existing

brines at room temperature.However,the alteration assem-blages in this study are forming at higher temperatures (>500°C)and the fractionation should be small,although the nature of the Cl complexing and behaviour in multi-ele-ment brines at high temperatures is unknown.The possibil-ity of higher temperature fractionation occurring is supported by one study that showed the presence of37Cl enriched silicates co-existing with a more negative?uid inclusion brine compositions(e.g.Eastoe and Guilbert, 1992;Eastoe et al.,1989).

Fig.5shows a simple Rayleigh fractionation calculation (adapted from Faure,1986)for a?uid starting with the lowest hypothesized mantle value(à1.6&)from the Bonifacie et al.(2008a)study(comparable with many of the data from Layne et al.,2009)and a range of values for the di?erence in the d37Cl(mineral)and the d37Cl(?uid).If we take a di?erence of 1.5&then the Greenstone and Porphyry hosted deposits would need to lose over90%of their37Cl to produce the lowest value in that system.This seems unreasonable.Reliable d37Cl values for silicate min-erals or rocks are sparse in the literature,but currently most data from these phases have slightly negative to slightly po-sitive d37Cl values(see Fig.6).If silicate mineral-?uid frac-tionation is modifying the isotopic signatures of these?uids then the fractionation factor must be higher than currently suggested by theoretical calculations.It is noteworthy that if fractionation between the mineralizing?uids and Cl bear-ing silicates has occurred and can generate more negative isotopic signatures in the mineralizing?uids then a crustal source for the Cl in these systems cannot be ruled out although the amount of fractionation would have to be even greater.Further work,on constraining the isotopic composition of the silicate phases will test this hypothesis.

5.2.NDZ hosted Cu mineralisation

The NDZ deposits are relatively Br enriched in compar-ison with the other two deposits types and with the

excep-Fig.5.Calculated Rayleigh fractionation curves(adapted from Faure,1986)for a?uid with an initial starting composition of the Mantle(A)taken from Bonifacie et al.(2008a,b)and the Crust(B) from Kaufmann et al.(1984).The numbers on the curves represent the di?erence between the d37Cl of the?uid and the mineral.F is the fraction of Cl in the system.

Chlorine isotopes in iron oxide–copper–gold deposits Sweden5667

tion of one sample have isotopic values around 0&.Although the Br/Cl ratios are higher they are still within the range for magmatic–hydrothermal ?uids (e.g.Kendrick et al.,2001;Nahnybida et al.,in press ).However,the isoto-pic signature of the chlorine is crustal and suggests that the chlorine in these deposits is ultimately derived from seawa-ter or evaporites and has retained this isotopic signature to the site of mineralisation.This may indicate (meta-)evapo-ritic input into the NDZ-related ?uids (Frietsch et al.,1997;Wanhainen et al.,2003),or that the ?uids are related to the granitic pegmatites of the Lina Suite,which have been interpreted to be crustal melts (Martinsson,2004).The sin-gle lower isotopic value has a comparable Br/Cl ratio and again we suggest that this sample it has been a?ected by fractionation with solid phases (Fig.3B).

https://www.doczj.com/doc/3516924096.html,parison to other Fe-oxide and IOCG provinces The microthermometric data suggest that the ?uids that formed the three deposit types are hypersaline,CaCl 2-rich,CO 2-bearing brines.Such ?uids have been indenti?ed in other IOGC provinces,most notably the Cloncurry depos-its (e.g.Williams et al.,2001;Pollard,2000;Williams and Pollard,2003;Fu et al.,2000;Fisher and Kendrick,2008),Olympic Dam (e.g.Oreskes and Einaudi,1992),Wernecke Breccias (Kendrick et al.,2008)and deposits in South America (e.g.Ripley and Ohmoto,1977;Marschik and Fontbote,2001).There have been some studies of the halogen ratio geochemistry of ?uid inclusions in these other deposits,particularly the deposits of the Cloncurry district.In total,a range of Br/Cl molar ratios of 0.3?10à3to 3.8?10à3have been described (e.g.Kendrick et al.,2007;Baker et al.,2008;Fisher and Kendrick 2008).In combina-tion with other data,particularly from noble gases,workers in this district have suggested that at Osborne the mineral-izing brines are ‘‘metamorphic ?uids ”derived initially from pore ?uids associated with evaporites or meta-evaporites with some locally derived metamorphic devolatilization products which then may have interacted with anatectic melts (Fisher and Kendrick,2008).At Ernest Henry,a model of mixing of magmatic ?uids with formation waters with salinities derived from halite dissolution has been sug-gested (Kendrick et al.,2007).A recent PIXE halogen study on single ?uid inclusions from Starra,Ernest Henry and Osborne gave Br/Cl ratios that range from 0.07to 3.2?10à3(Baker et al.,2008)and these authors also inter-pret their data to suggest mixing of magmatic ?uids with other brines.

A single study has measured isotopic values and halogen ratios on bulk ?uid inclusion leachates from South

Ameri-

https://www.doczj.com/doc/3516924096.html,parison of Cl isotopic values from this study with some other published data from mineral,?uids and ?uid inclusion studies (1Luders et al.,2002;2Germann et al.,2003;3Chiaradia et al.,2006;4Eastoe and Guilbert,1992;5Nahnybida et al.,in press ;6,7Banks et al.,2000a,b ;8Ransom et al.,1995;9Wei et al.,2008;10Godon et al.,2004a,b ;11Eastoe et al.,2001;12Eastoe et al.,1999;13Bonifacie et al.,2005;14

Arcuri and Brimhall,200315Eggenkamp et al.,1995;16Eastoe et al.,2007;17Barnes and Sharp,2006;18Bonifacie et al.,2008b ;19Hanley et al.,2006;20Sharp et al.,2007;21Bonifacie et al.,2007;22Bonifacie et al.,2008a ;23Layne et al.,2009;24Eggenkamp and van Groos,1997;25

John et al.,2008).

5668S.A.Gleeson,M.P.Smith /Geochimica et Cosmochimica Acta 73(2009)5658–5672

can deposits including Candelaria and Raul-Constable.The Br/Cl and d37Cl values range from0.12to1.35andà0.58& to+2.10&,respectively(Chiaradia et al.,2006).In the light of these data these authors also suggest that the deposits formed by mixing of a mantle derived component and basi-nal brines although their model was dependant on the sug-gestion that the mantle has a strongly positive d37Cl value, which has recently been strongly disputed(Sharp et al., 2007;Bonifacie et al.,2007,2008a,b).Nevertheless their data strongly supports?uid mixing.

Unlike many of these studies,the data from the Norr-botten area has a more restricted range of Br/Cl ratios,sug-gesting that mixing occurred between?uids with similar halogen compositions and total salinities.A previous sul-phur isotope study in Norrbotten does suggest there are two sources of sulphur in the deposits;magmatic sulphur and sulphur which has been derived from bacterial sulphate reduction and added to the system by interaction with the metasedimentary or volcanic units in the sequence(Frietsch et al.,1997).Our data do not rule out an evaporitic source of the Cl in the Fe-oxide–apatite and Porphyry and Green-stone hosted deposits but we believe a mantle or magmatic source of chlorine to be more likely for most of the samples.

A recent halogen and noble gas isotope study of the Wer-necke Breccias in Canada(Kendrick et al.,2008)also found a component of magmatic?uids in those systems(mixed with sedimentary formation waters).However,a crustal source for Cl in the NDZ deposits is strongly supported by our data.

The results presented here,therefore,are on the whole signi?cantly di?erent to the d37Cl data presented in Chiara-dia et al.(2006)which con?rms,as has been suggested by other authors(Williams et al.,2005),di?erent IOGC depos-its may have di?erent origins and constructing a single ge-netic model for all these deposits is problematic.

6.CONCLUSIONS

Late-stage quartz veins in Fe-oxide–apatite deposits from Norrbotten,are dominated by saline?uid inclusions and leachates from these samples have a wide range of Br/Cl molar ratios,from0.2to1.1?10à3and d37Cl values fromà3.1&toà1.0&.The Br/Cl ratios of these leachates are consistent with the derivation of salinity from magmatic sources or halite dissolution.One sample has an isotopic value that overlaps the range for the crustal Cl reservoir but most of the data have isotopic compositions in the range of data from MORB glasses and inclusions.

Leachates from saline?uid inclusions from the Green-stone and Porphyry hosted Cu–Au prospects have a more narrow range in halogen ratios,from0.2to0.5?10à3 but a wider range in d37Cl values fromà5.6&toà1.3&. The halogen and the upper range of the d37Cl values in these samples suggest a source of magmatic Cl in these hydrothermal systems,similar to the Fe-oxide–apatite deposits.However,we suggest that the more negative d37Cl values found in both deposit types are the result of the modi?cation of the Cl-isotope signature is due to frac-tionation occurring between the mineralising?uids and Cl-rich silicate assemblages found in the alteration haloes around the deposits.If such a processes is occurring then all the data could be shifted to more negative values and a crustal source for the Cl,although unlikely,cannot be de?nitively ruled out.

Finally,the Cu–Au deposits hosted by the Nautanen Deformation Zone(NDZ)have Br/Cl molar ratios from 0.4to 1.1?10à3and d37Cl values that range from à2.4&to+0.5&and this suggests that the source of Cl in the NDZ deposits has a crustal signature,which suggests the Cl in this system may be derived from(meta-)evapor-ites or from input from crustal melts such as granitic peg-matites of the Lina Suite.

ACKNOWLEDGMENTS

This study was funded by European Union Regional Develop-ment Fund Georange Program Grant89121and an NSERC dis-covery grant to SG.Craig Storey assisted with?eld work in Sweden.SG would like to acknowledge the assistance of Taras Nahnybida.This manuscript was greatly improved by the thought-ful and constructive reviews of A.Boudreau,Murray Hitzman, Mark Kendrick,Zach Sharp and an anonymous reviewer.We greatly appreciate their e?orts.

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Associate editor:Edward M.Ripley

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射频阻抗匹配与史密斯_Smith_圆图：基本原理详解

阻抗匹配与史密斯(Smith)圆图：基本原理
在处理 RF 系统的实际应用问题时，总会遇到一些非常困难的工作，对各部分级联电路的不同阻抗进行匹配就是其中之一。一般情况下，需要进行匹配的电路包括天线与低噪声放大器(LNA)之间的匹配、功率放大器输出(RFOUT)与天线之间的匹配、 LNA/VCO 输出与混频器输入之间的匹配。匹配的目的是为了保证信号或能量有效地从“信号源”传送到“负载”。
在高频端，寄生元件(比如连线上的电感、板层之间的电容和导体的电阻)对匹配网络具有明显的、不可预知的影响。频率在数十兆赫兹以上时，理论计算和仿真已经远远不能满足要求，为了得到适当的最终结果，还必须考虑在实验室中进行的 RF 测试、并进行适当调谐。需要用计算值确定电路的结构类型和相应的目标元件值。
有很多种阻抗匹配的方法，包括
?
计算机仿真：由于这类软件是为不同功能设计的而不只是用于阻抗匹配，所以使用起来比较复杂。设计者必须熟悉用正确的格式输入众多的数据。设计人员还需要具有从大量的输出结果中找到有用数据的技能。另外，除非计算机是专门为这个用途制造的，否则电路仿真软件不可能预装在计算机上。
? ? ?
手工计算：这是一种极其繁琐的方法，因为需要用到较长(“几公里”)的计算公式、并且被处理的数据多为复数。经验：只有在 RF 领域工作过多年的人才能使用这种方法。总之，它只适合于资深的专家。史密斯圆图：本文要重点讨论的内容。
本文的主要目的是复习史密斯圆图的结构和背景知识，并且总结它在实际中的应用方法。讨论的主题包括参数的实际范例，比如找出匹配网络元件的数值。当然，史密斯圆图不仅能够为我们找出最大功率传输的匹配网络，还能帮助设计者优化噪声系数，确定品质因数的影响以及进行稳定性分析。
图 1. 阻抗和史密斯圆图基础
基础知识
在介绍史密斯圆图的使用之前，最好回顾一下 RF 环境下(大于 100MHz) IC 连线的电磁波传播现象。这对 RS-485 传输线、PA 和天线之间的连接、LNA 和下变频器/混频器之间的连接等应用都是有效的。

如何用好Word模板

巧妙地利用Office模板可以大大方便我们的操作。Word中更是添加了众多好用的模板文件，但是你知道它们到底怎样用吗?如何才能够让它们用得更好? Word模板的分类及分布 Word中的模板分为两类:一是系统向导和模板，第二类为用户自定义模板。而Word的系统向导和模板默认安装在C:\Program Files\Microsoft Office\Templates\2052文件夹中，其扩展名是WIZ(向导)和DOT(模板)。而用户自定义模板存放的位置会由于Windows版本的不同而不一样：对于windows 2000/NT/XP用户，自定义模板会放到C:\Documents and Settings\Administrator\Application Data\Microsoft\Templates 文件夹下；如果使用Windows 9x/Me，模板会被放置到C:\Windows\Application Data\Microsoft\Templates 文件夹下。使用现有模板 Office XP本身准备了很多精美模板，只要选择“文件”→“新建”，在Word窗口右侧会出现“新建文件”窗口任务格，单击“根据模板新建”下的“通用模板”项目弹出“模板”选择窗口。在这里所有模板已经分门别类放置好了，有常用、Web 页、报告、备忘录、出版物、其他文件、信函和传真、英文向导模板等几类向导或模板，而且可以单击相应标签打开，其中会有相应模板文件名及模板描述信息，并可预览。选中你需要的模板，然后单击“确定”按钮即可打开已经套用该模板的新文件。有的模板可能还会打开向导窗口要求你进行一些参数的设置与设置。安装外部模板模板以文件的形式存放的。因此，如果从网上或光盘上找到一些Word模板，只要把它们拷贝到 C:\Documents and Settings\Administrator\Application Data\Microsoft\Templates文件夹下(windows 2000/XP用户)或C:\Windows\Application Data\Microsoft\Templates文件夹下即可(Windows 9x/Me用户)。删除不必要的模板如果不需要太多模板，或觉得安装了太多模板，可打开“资源管理器”，进入用户自定义模板文件夹，再把相应的模板文件删除掉即可。把别人的文档用作模板如果看到某一篇文件比较漂亮，且能用Word打开它，那么可选择“文件”→“另存为”，然后再在“另存为”对话框中的“保存类型”下拉框中选择“文件模板”，再输入一个文件名，并把它保存到默认的模板文件夹下。以后只要选择“文件”→“新建”，就可以在“常规”模板标签中看到刚才制作的模板，双击后即可使用自己定制的模板了。通过此法，就可以快速把DOC文件转换为Word的模板。

Smith圆图概述

一、Smith圆图概述 Smith圆图（Smith chart）是用来分析传输线匹配问题的有效方法。它具有概念明晰、求解直观、精度高等特点，因而被广泛应用于射频工程中分析传输线问题。高频与微波电路设计中，最基本且重要的课题为阻抗匹配。透过阻抗匹配的运用与设计，可以使信号有效率的由电源端传送到负载端。现阶段，阻抗匹配须借重史密斯图的运用才能快速、有效的达成。随着时间的流转，阻抗匹配的方式也由过去在史密斯图上以手绘计算结果，转而经由计算机化的史密斯图达成，其优点在于：(1)免除复杂计算过程中可能产生的人为错误，(2)透过计算机化史密斯图的运用可以进一步达到宽频带阻抗匹配的目的。电子SMITH圆图软件能将计算结果以图形和数据并行输出，处理包括复数的矩阵运算。且拥有良好的用户界面以及函数本身会绘制图形、自动选取坐标刻度等优点。本设计即是利用vb6.0针对阻抗匹配设计的计算机化史密斯图。其优点在于图面功能非常清楚，并且运用可视化的安排，使匹配电路直接显示，使设计者可以轻松的了解如何进行阻抗匹配工作也同时可以观察加入各项组件后的输入阻抗变化情形。

二、Smith圆图结构阻抗圆导纳圆阻抗圆导纳圆反射系数圆软件界面电抗圆电阻圆

三、Smith圆图基本原理史密斯圆图是由很多圆周交织在一起的一个图。正确的使用它，可以在不作任何计算的前提下得到一个表面上看非常复杂的系统的匹配阻抗，唯一需要作的就是沿着圆周线读取并跟踪数据。史密斯圆图是反射系数(伽马，以符号Γ表示)的极座标图。反射系数也可以从数学上定义为单端口散射参数，即s11。史密斯圆图是通过验证阻抗匹配的负载产生的。这里我们不直接考虑阻抗，而是用反射系数ΓL，反射系数可以反映负载的特性(如导纳、增益、跨导)，在处理RF频率的问题时ΓL更加有用。我们知道反射系数定义为反射波电压与入射波电压之比：图3. 负载阻抗负载反射信号的强度取决于信号源阻抗与负载阻抗的失配程度。反射系数的表达式定义为：

Word模板使用

Word模板使用用Word编排文档时，我们时时刻刻都在使用模板，或许您还不知道，或许您已知道，但对模板抱有神秘感，不知道怎么使用它，更不用说如何修改和创建符合自己需要的模板了。其实文档模板也是一种Word文档，只是比普通的文档多了一个内容罢了。 1.模板的概念模板是一类特殊的文档，它可以提供完成最终文档所需要的基本工具，一般包含以下内容：同类文档中都相同的文本：每篇文档中都需要的文字和图形，比如页眉和页脚；用于插入日期、时间、文件名和文档标题等信息的域；固定的图文标识；公司徽标等；页面格式：用“文件”菜单的“页面设置”命令设置的页边距和其它页面选项；样式：它们是格式化文档所必须的工具；自动图文集词条：以自动图文集词条形式保存的文字或图形，以便快速地向文档添加相同的文本和图形；宏命令；占位文字：其实是一个域，单击它可以选定域，然后输入对应的内容，以便快速地套用文档模板的排版格式；自定义菜单项、快捷键、工具栏。模式是为了加速文档的编撰过程而建立的，您可以使用Word提供的模板来创建新文档，以模板提供的文本、图形和格式为蓝图，快速地编写文档，以节省时间和精力。Word提供了许多常见文档类型的模板，如备忘录、报告、传真、商务信件、简历等。您可以直接利用这些模板，也可以对它们加以修改，或创建符合自己要求的模板。在创建文档时，如果您不选用其它模板，Word默认使用默认模板。 1.1模板的种类模板分为普通模板和特殊模板两类。特殊模板包括向导和默认模板两种，除此之外的模板都是普通模板。普通模板中有一种较为特殊的模板叫共用模板，它不是因为具有什么特别的属性，而是由于对它进行了特殊的处理，使其具有特殊的使用属性。默认模板和共用模板又统称为通用模板。

史密斯(Smith)圆图

阻抗匹配与史密斯 (Smith) 圆图：基本原理摘要：本文利用史密斯圆图作为 RF 阻抗匹配的设计指南。文中给出了反射系数、阻抗和导纳的作图范例，并给出了 MAX2474 工作在 900MHz 时匹配网络的作图范例。事实证明，史密斯圆图仍然是确定传输线阻抗的基本工作。在处理 RF 系统的实际应用问题时，总会遇到一些非常困难的工作，对各部分级联电路的不同阻抗进行匹配就是其中之一。一般情况下，需要进行匹配的电路包括天线与低噪声放大器 (LNA) 之间的匹配、功率放大器输出 (RFOUT) 与天线之间的匹配、 LNA/VCO 输出与混频器输入之间的匹配。匹配的目的是为了保证信号或能量有效地从“信号源”传送到“负载”。在高频端，寄生元件 (比如连线上的电感、板层之间的电容和导体的电阻 ) 对匹配网络具有明显的、不可预知的影响。频率在数十兆赫兹以上时，理论计算和仿真已经远远不能满足要求，为了得到适当的最终结果，还必须考虑在实验室中进行的 RF 测试、并进行适当调谐。需要用计算值确定电路的结构类型和相应的目标元件值。有很多种阻抗匹配的方法，包括计算机仿真：由于这类软件是为不同功能设计的而不只是用于阻抗匹配，所以使用起来比较复杂。设计者必须熟悉用正确的格式输入众多的数据。设计人员还需要具有从大量的输出结果中找到有用数据的技能。另外，除非计算机是专门为这个用途制造的，否则电路仿真软件不可能预装在计算机上。手工计算：这是一种极其繁琐的方法，因为需要用到较长 (“几公里”)的计算公式、并且被处理的数据多为复数。经验：只有在 RF 领域工作过多年的人才能使用这种方法。总之，它只适合于资深的专家。史密斯圆图：本文要重点讨论的内容。本文的主要目的是复习史密斯圆图的结构和背景知识，并且总结它在实际中的应用方法。讨论的主题包括参数的实际范例，比如找出匹配网络元件的数值。当然，史密斯圆图不仅能够为我们找出最大功率传输的匹配网络，还能帮助设计者优化噪声系数，确定品质因数的影响以及进行稳定性分析。图 1. 阻抗和史密斯圆图基础

s参数与史密斯圆图

s参数与史密斯圆图 Company Document number：WTUT-WT88Y-W8BBGB-BWYTT-19998

阻抗匹配与史密斯(Smith)圆图: 基本原理本文利用史密斯圆图作为RF阻抗匹配的设计指南。文中给出了反射系数、阻抗和导纳的作图范例，并用作图法设计了一个频率为60MHz的匹配网络。实践证明：史密斯圆图仍然是计算传输线阻抗的基本工具。在处理RF系统的实际应用问题时，总会遇到一些非常困难的工作，对各部分级联电路的不同阻抗进行匹配就是其中之一。一般情况下，需要进行匹配的电路包括天线与低噪声放大器(LNA)之间的匹配、功率放大器输出(RFOUT)与天线之间的匹配、LNA/VCO输出与混频器输入之间的匹配。匹配的目的是为了保证信号或能量有效地从“信号源”传送到“负载”。在高频端，寄生元件(比如连线上的电感、板层之间的电容和导体的电阻)对匹配网络具有明显的、不可预知的影响。频率在数十兆赫兹以上时，理论计算和仿真已经远远不能满足要求，为了得到适当的最终结果，还必须考虑在实验室中进行的RF测试、并进行适当调谐。需要用计算值确定电路的结构类型和相应的目标元件值。有很多种阻抗匹配的方法，包括: ?计算机仿真:由于这类软件是为不同功能设计的而不只是用于阻抗匹配，所以使用起来比较复杂。设计者必须熟悉用正确的格式输入众多的数据。设计人员还需要具有从大量的输出结果中找到有用数据的技能。另外，除非计算机是专门为这个用途制造的，否则电路仿真软件不可能预装在计算机上。 ?手工计算:这是一种极其繁琐的方法，因为需要用到较长(“几公里”)的计算公式、并且被处理的数据多为复数。 ?经验:只有在RF领域工作过多年的人才能使用这种方法。总之，它只适合于资深的专家。 ?史密斯圆图: 本文要重点讨论的内容。本文的主要目的是复习史密斯圆图的结构和背景知识，并且总结它在实际中的应用方法。讨论的主题包括参数的实际范例，比如找出匹配网络元件的数值。当然，史密斯圆图不仅能够为我们找出最大功率传输的匹配网络，还能帮助设计者优化噪声系数，确定品质因数的影响以及进行稳定性分析。图1. 阻抗和史密斯圆图基础基础知识在介绍史密斯圆图的使用之前，最好回顾一下RF环境下(大于100MHz) IC连线的电磁波传播现象。这对RS-485传输线、PA和天线之间的连接、LNA和下变频器/混频器之间的连接等应用都是有效的。大家都知道，要使信号源传送到负载的功率最大，信号源阻抗必须等于负载的共轭阻抗，即： R s + jX s = R L - jX L 图2. 表达式R s + jX s = R L - jX L的等效图在这个条件下，从信号源到负载传输的能量最大。另外，为有效传输功率，满足这个条件可以避免能量从负载反射到信号源，尤其是在诸如视频传输、RF或微波网络的高频应用环境更是如此。史密斯圆图史密斯圆图是由很多圆周交织在一起的一个图。正确的使用它，可以在不作任何计算的前提下得到一个表面上看非常复杂的系统的匹配阻抗，唯一需要作的就是沿着圆周线读取并跟踪数据。史密斯圆图是反射系数(伽马，以符号表示)的极座标图。反射系数也可以从数学上定义为单端口散射参数，即s11。史密斯圆图是通过验证阻抗匹配的负载产生的。这里我们不直接考虑阻抗，而是用反射系数L，反射系数可以反映负载的特性(如导纳、增益、跨导)，在处理RF频率的问题时，L更加有用。我们知道反射系数定义为反射波电压与入射波电压之比: 图3. 负载阻抗负载反射信号的强度取决于信号源阻抗与负载阻抗的失配程度。反射系数的表达式定义为：由于阻抗是复数，反射系数也是复数。为了减少未知参数的数量，可以固化一个经常出现并且在应用中经常使用的参数。这里Z o (特性阻抗)通常为常数并且是实数，是常用的归一化标准值，如50、75、100和600。于是我们可以定义归一化的负载阻抗：

SMITH圆图分析与归纳

《射频电路》课程设计题目：SMITH圆图分析与归纳系部电子信息工程学院学科门类工学专业电子信息工程学号姓名 2012年6月25日

SMITH 圆图分析与归纳摘要 Smith 圆图在计算机时代就开发了，至今仍被普遍使用，几乎所有的计算机辅助设计程序都应用Smith 圆图进行电路阻抗的分析、匹配网路的设计及噪声系数、增益和环路稳定性的计算。在Smith 圆图中能简单直观地显示传输线阻抗以及反射系数。 Smith 圆图是在反射系数复平面上，以反射系数圆为低圆，将归一化阻抗圆或归一化导纳圆盖在底图上而形成的。因而Smith 圆图又分为阻抗圆图和导纳圆图。关键字：Smith 圆图阻抗圆图导纳圆图归一化阻抗圆归一化导纳圆一引言通过对射频电路的学习，使我对射频电路的视野得到了拓宽，以前自己的视野只局限于低频电路的设计，从来没考虑过波长和传输线之间的关系，而且从来没想过，一段短路线就可以等效为一个电感，一段开路线可以等效为一个电容，一条略带厚度的微带竟然可以传输电波，然而在低频电路我们只把它当做一条阻值可以忽略的导线，同时在低频电路设计时好多原件，都要自己手动计算，然而在学习射频电路时，我发现我们不仅要考虑波长和传输线之间的关系，同时还要考虑每一条微带的长度和宽度，当然我感到最重要的是，通过Smith 圆图可以大大的简化了，我对电阻和电容的计算，二史密斯圆图功能分析 2.1 史密斯圆图的基本基本知识史密斯圆图的基本在于以下的算式： )0/()0(Z ZL Z ZL +-=Γ Γ代表其线路的反射系数，即散射矩阵里的S11，Z 是归一负载值，即0/Z ZL 。当中，ZL 是线路的负载值，Z0是传输线的特征阻抗值，通常会使用50Ω。圆图中的横坐标代表反射系数的实部，纵坐标代表虚部。圆形线代表等电阻圆，每个圆的圆心为()1/(+R R ,0),半径为)1/(1+R 。R 为该圆上的点的电阻值。中间的横线与向上和向下散出的线则代表阻抗的虚数值，即等电抗圆，圆心为(1，X /1),半径为X /1。由于反射系数是小于等于1的，所以在等电抗圆落在单位圆以外的部分没有意义。当中向上发散的是正数，向下发散的是负数。圆图最中间的点(01J Z +=,0=Γ)代表一个已匹配的电阻数值(此ZL=Z0，即1=Z )，同时其反射系数的值会是零。圆图的边缘代表其反射系数的幅度是1，即100%反射。在图边的数字代表反射系数的角度(0-180度)。有一些圆图是以导纳值来表示，把上述的阻抗值版本旋转180度即可。圆图中的每一点代表在该点阻抗下的反射系数。该电的阻抗实部可以从该电所在的等

阻抗匹配中Smith圆图的巧妙使用

阻抗匹配与史密斯(Smith)圆图_基本原理

手工计算: 这是一种极其繁琐的方法，因为需要用到较长(“几公里”)的计算公式、并且被处理的数据多为复数。经验: 只有在RF领域工作过多年的人才能使用这种方法。总之，它只适合于资深的专家。史密斯圆图: 本文要重点讨论的内容。本文的主要目的是复习史密斯圆图的结构和背景知识，并且总结它在实际中的应用方法。讨论的主题包括参数的实际范例，比如找出匹配网络元件的数值。当然，史密斯圆图不仅能够为我们找出最大功率传输的匹配网络，还能帮助设计者优化噪声系数，确定品质因数的影响以及进行稳定性分析。图1. 阻抗和史密斯圆图基础基础知识在介绍史密斯圆图的使用之前，最好回顾一下RF环境下(大于100MHz) IC连线的电磁波传播现象。这对RS-485传输线、PA和天线之间的连接、LNA和下变频器/混频器之间的连接等应用都是有

史密斯圆图基本原理

阻抗匹配与史密斯(Smith)圆图：基本原理摘要：本文利用史密斯圆图作为RF阻抗匹配的设计指南。文中给出了反射系数、阻抗和导纳的作图范例，并给出了MAX2474工作在900MHz时匹配网络的作图范例。事实证明，史密斯圆图仍然是确定传输线阻抗的基本工作。在处理RF系统的实际应用问题时，总会遇到一些非常困难的工作，对各部分级联电路的不同阻抗进行匹配就是其中之一。一般情况下，需要进行匹配的电路包括天线与低噪声放大器(LNA)之间的匹配、功率放大器输出(RFOUT)与天线之间的匹配、LNA/VCO输出与混频器输入之间的匹配。匹配的目的是为了保证信号或能量有效地从“信号源”传送到“负载”。在高频端，寄生元件(比如连线上的电感、板层之间的电容和导体的电阻)对匹配网络具有明显的、不可预知的影响。频率在数十兆赫兹以上时，理论计算和仿真已经远远不能满足要求，为了得到适当的最终结果，还必须考虑在实验室中进行的RF测试、并进行适当调谐。需要用计算值确定电路的结构类型和相应的目标元件值。有很多种阻抗匹配的方法，包括计算机仿真：由于这类软件是为不同功能设计的而不只是用于阻抗匹配，所以使用起来比较复杂。设计者必须熟悉用正确的格式输入众多的数据。设计人员还需要具有从大量的输出结果中找到有用数据的技能。另外，除非计算机是专门为这个用途制造的，否则电路仿真软件不可能预装在计算机上。手工计算：这是一种极其繁琐的方法，因为需要用到较长(“几公里”)的计算公式、并且被处理的数据多为复数。经验：只有在RF领域工作过多年的人才能使用这种方法。总之，它只适合于资深的专家。史密斯圆图：本文要重点讨论的内容。本文的主要目的是复习史密斯圆图的结构和背景知识，并且总结它在实际中的应用方法。讨论的主题包括参数的实际范例，比如找出匹配网络元件的数值。当然，史密斯圆图不仅能够为我们找出最大功率传输的匹配网络，还能帮助设计者优化噪声系数，确定品质因数的影响以及进行稳定性分析。图1. 阻抗和史密斯圆图基础

阻抗匹配与史密斯(Smith)圆图基本原理

Word模板使用全解析

Word模板使用全解析大部分Word用户都有使用模板的经历，不管你是否意识到，模板确实是提高工作效率的另一重要途径。那些希望使自己制作的各种企业文档统一规范的朋友，通过样式和模板的组合使用，可以得到完整的解决方案。本文将在前面介绍过的Word样式的基础上，进一步学习获得和实施文档统一规范解决方案所需的各种基本能力，并且学习使用模板提高实际工作效率所需的必备基本技能。对于那些需要常常处理具有规律和重复性的文档(例如会议通知、企业公文、客户信函、传真等)的朋友来说，模板将是你梦寐以求的工具。一、应用性任务通常，学习的动力来源于实际中的问题和任务的激发。在开始具体内容之前，我们也提出两个实际的问题和任务，学习完成之后，检查一下自己是否获得解决问题和完成任务的能力。 (一) 如何利用现有模板提高工作效率？我们知道，Word提供了各式各样的模板，当我们在制作专业的文档之前，看看有没有现成的模板可用，如果答案是肯定的，那么就发挥“拿来主义”的精神吧，利用现成的模板不管是效率还是质量都是非常可观的。 (二) 如何让企业的文档统一和规范？这个任务在样式部分的课程中就曾经提过，这里我们希望学习模板的各种技能后，结合样式的运用，就能获得完整的解决方案，这个任务更加具体的说法就是，如何创建适合自己企业需要的模板。二、基本应用能力训练 (一) 理解模板的概念为了我们能更好的使用模板，一开始先来讨论一下模板的概念。前面所提到的“模板”，实际上是“模板文件”的简称，也就是说“模板”是一种特殊的文件，在其他文件创建时使用它。也许初学Word的朋友会问，难道我在Word中单击“新建空白文档”，创建一个空白的文档，也使用模板了吗？是的，这时候Word使用了Normal模板来创建了一个新文档。当然，如果你通过单击“本机上的模板”或“网站上的模板”，在弹出的对话框中，选择其他特殊的模板来创建文档时，在文档创建时使用了模板是容易理解的。实际上，每个模板都提供了一个样式集合，供我们格式化文档使用。除了样式之外，模板还包含其它元素，比如宏、自动图文集、自定义的工具栏等。因此我们可以把模板形象地理解成一个容器，它包含上面提到的各种元素。不同功能的模板包含的元素当然也不尽相同，而一个模板中的这些元素，在我们处理同一

使用模板教案

《使用模板》教案课型：新授教学目标： 1、学会使用Word的任务窗格 2、会利用Word的模板向导制作生成实用文档重点：利用Word模板向导制作生成实用文档难点：从网站上下载实用模板教法：目标驱动，引导学法：探索与训练教具：能上网的教师电脑与学生电脑，office完全安装素材准备：制作日历、名片所用到的图片授课过程一、问题导入：师展示一张用Word 2003制作好的日历，大家知道这是如何制作出来的吗？（学生回答），其实用Word 2003就可以制作出这样的作品，同学们想不想也来做一个日历，来为我们的学习生活提供一些帮助呢？（生很有兴趣）今天我们大家就自己做一个这样的作品。二、授课过程（通过两个实用文稿制作完成教学任务） 1、活动一利用日历向导制作日历的过程师引导学生参考教材34页的操作训练内容制作日历，并提供所用素材的位置，另外要求学生注意学习有关任务窗格、向导等述语和名词，教师观察学生制作，并做指导教师请部分学生演示自己的制作过程（尽量有讲解过程），并指出什么是“任务窗格”，什么是“向导”。教师与全班同学一起点评，鼓励学生继续努力，使作品更完善、更美观。师引导学生完善自己的作品，并将作品保存在机房公共目录中，与其它同学共享成果。 2、活动二用“名片向导”制作名片引导学生按教材37页的操作训练步骤进行名片制作，比一比那一位同学制

作的最好，将评出三幅作品进行奖励。教师巡回观察，并及时指导。利用电子屏幕对学生作品进行公开展评，评出优秀作品进行奖励。 3、从网站上下载实用的模板除了Word本身所提供的模板向导功能以外，同学们还可以从微软office网站上下载更多、更新的模板（师展示从网上下载的模板作品），同学们想试一试想吗？（学生跃跃欲试）引导学生从新建任务窗格中找到搜索模板条，输入要查找的模板名称，进行搜索。查找到相应的内容后，选择下载使用。找学生为全班演示（尽量有讲解过程），教师适当点评，强调并不是所有网上的模板都能用，学生需要选择当前office版本所支持的模板。教师要求学生将完成的作品上传到学校机房的共享目录中，以便与其他同学共同分享学习成果。 3、总结本节课的内容通过今天的学习，同学们学会了利用Word的模板向导功能制作日历与名片，并认识了什么是Word的任务窗格，其实，Word的模板还不至这些（教师展示其它类型的模板作品比如：个人简历、请柬、海报、通知书等），希望同学们在今后的学习中，多动手、多尝试，创作出更精彩、更实用的作品，为我们的学习生活增添一份快乐吧！ 1

史密斯圆图简介

史密斯圆图（Smith chart ）分析长线的工作状态离不开计算阻抗、反射系数等参数，会遇到大量繁琐的复数运算，在计算机技术还未广泛应用的过去，图解法就是常用的手段之一。在天线和微波工程设计中，经常会用到各种图形曲线，它们既简便直观，又具有足够的准确度，即使计算机技术广泛应用的今天，它们仍然对天线和微波工程设计有着重要的影响作用。Smith chart 就是其中最常用一种。 1、Smith chart 的构成在Smith chart 中反射系数和阻抗一一对应；Smith chart 包含两部分，一部分是阻抗Smith 圆图（Z-Smith chart ），它由等反射系数圆和阻抗圆图构成；另外一部分是导纳Smith 圆图（Y-Smith chart ），它由等反射系数圆和导纳圆图构成；它们共同构成YZ-Smith chart 。阻抗圆图又由电阻和电抗两部分构成，导纳圆图由电导和电纳构成。 1.1 等反射系数圆在如图1所示的带负载的传输线电路图中，由长线理论的知识我们可以得到负载处的反射系数0 Γ为： 000000 L j L u v L Z Z j e Z Z θ-Γ==Γ+Γ=Γ+ 其中00arctan(/)L v u θ =ΓΓ 。图1 带负载的传输线电路图

在离负载距离为z 处的反射系数Γ为： 2000 L j j z in u v in Z Z j e e Z Z θβ--Γ==Γ+Γ=Γ+ 其中220 u v Γ= Γ+Γ，arctan(/)L v u θ=ΓΓ。椐此我们用极坐标当负载和传输线的特征阻抗确定下来之后，传输线上不同位置处的反射系数辐值（1Γ≤）将不再改变，而变得只是反射系数的辐角；辐角的变化为2z β-?，传输线上的位置向负载方向移动时，辐角逆时针转动，向波源方向移动时，辐角向顺时针方向转动，如图2 所示。图2 等反射系数圆传输线上不同位置处的反射系数的辐角变化只与2z β-，其中传波常数 2/p βπλ=，所以Γ是一个周期为0.5p λ的周期性函数。

史密斯圆图地详解

本文利用史密斯圆图作为RF阻抗匹配的设计指南。文中给出了反射系数、阻抗和导纳的作图范例，并用作图法设计了一个频率为60MHz的匹配网络。在处理RF系统的实际应用问题时，总会遇到一些非常困难的工作，对各部分级联电路的不同阻抗进行匹配就是其中之一。一般情况下，需要进行匹配的电路包括天线与低噪声放大器(LNA)之间的匹配、功率放大器输出(RFOUT)与天线之间的匹配、LNA/VCO输出与混频器输入之间的匹配。匹配的目的是为了保证信号或能量有效地从“信号源”传送到“负载”。在高频端，寄生元件(比如连线上的电感、板层之间的电容和导体的电阻)对匹配网络具有明显的、不可预知的影响。频率在数十兆赫兹以上时，理论计算和仿真已经远远不能满足要求，为了得到适当的最终结果，还必须考虑在实验室中进行的RF测试、并进行适当调谐。需要用计算值确定电路的结构类型和相应的目标元件值。有很多种阻抗匹配的方法，包括: 计算机仿真: 由于这类软件是为不同功能设计的而不只是用于阻抗匹配，所以使用起来比较复杂。设计者必须熟悉用正确的格式输入众多的数据。设计人员还需要具有从大量的输出结果中找到有用数据的技能。另外，除非计算机是专门为这个用途制造的，否则电路仿真软件不可能预装在计算机上。手工计算: 这是一种极其繁琐的方法，因为需要用到较长(“几公里”)的计算公式、并且被处理的数据多为复数。经验: 只有在RF领域工作过多年的人才能使用这种方法。总之，它只适合于资深的专家。史密斯圆图: 本文要重点讨论的内容。本文的主要目的是复习史密斯圆图的结构和背景知识，并且总结它在实际中的应用方法。讨论的主题包括参数的实际范例，比如找出匹配网络元件的数值。当然，史密斯圆图不仅能够为我们找出最大功率传输的匹配网络，还能帮助设计者优化噪声系数，确定品质因数的影响以及进行稳定性分析。图1. 阻抗和史密斯圆图基础图1. 阻抗和史密斯圆图基础

通俗讲解史密斯圆图

不管这是今天1、是2、为3、干 1、是该图“在我史密当中管多么经典的射是什么东东？天解答三个问题是什么？为什么？干什么？是什么？表是由菲利普我能够使用计算密斯图表的基本的Γ代表其线射频教程，为什题：普·史密斯(Phillip 算尺的时候，我本在于以下的算线路的反射系数从容面对“史什么都做成黑白p Smith)于193我对以图表方式算式。数(reflection coe 史密斯圆图白的呢？让想理39年发明的，当式来表达数学上efficient) ”，不再懵逼理解史密斯原图当时他在美国的上的关联很有兴图的同学一脸懵的RCA 公司工作兴趣”。懵逼。作。史密斯曾说说过，

即S参数（S-parameter）里的S11，ZL是归一负载值，即ZL / Z0。当中，ZL是线路本身的负载值，Z0是传输线的特征阻抗（本征阻抗）值，通常会使用50?。简单的说：就是类似于数学用表一样，通过查找，知道反射系数的数值。 2、为什么？我们现在也不知道，史密斯先生是怎么想到“史密斯圆图”表示方法的灵感，是怎么来的。很多同学看史密斯原图，屎记硬背，不得要领，其实没有揣摩，史密斯老先生的创作意图。我个人揣测：是不是受到黎曼几何的启发，把一个平面的坐标系，给“掰弯”了。我在表述这个“掰弯”的过程，你就理解，这个图的含义了。（坐标系可以掰弯、人尽量不要“弯”；如果已经弯了，本人表示祝福）现在，我就掰弯给你看。世界地图，其实是一个用平面表示球体的过程，这个过程是一个“掰直”。史密斯原图，巧妙之处，在于用一个圆形表示一个无穷大的平面。

2.1、首先，我们先理解“无穷大”的平面。首先的首先，我们复习一下理想的电阻、电容、电感的阻抗。在具有电阻、电感和电容的电路里，对电路中的电流所起的阻碍作用叫做阻抗。阻抗常用Z表示，是一个复数，实际称为电阻，虚称为电抗，其中电容在电路中对交流电所起的阻碍作用称为容抗,电感在电路中对交流电所起的阻碍作用称为感抗，电容和电感在电路中对交流电引起的阻碍作用总称为电抗。阻抗的单位是欧姆。 R，电阻：在同一电路中，通过某一导体的电流跟这段导体两端的电压成正比，跟这段导体的电阻成反比,这就是欧姆定律。标准式：。（理想的电阻就是实数，不涉及复数的概念）。如果引入数学中复数的概念，就可以将电阻、电感、电容用相同的形式复阻抗来表示。既：电阻仍然是实数R（复阻抗的实部），电容、电感用虚数表示，分别为：

【最新推荐】ppt如何加载模板-范文模板 (6页)

本文部分内容来自网络整理，本司不为其真实性负责，如有异议或侵权请及时联系，本司将立即删除！ == 本文为word格式，下载后可方便编辑和修改！ == ppt如何加载模板篇一：PPT模板下载后怎么用 ppt模板下载后怎么用是母版吗？，ppt文件，你就直接把他放到c:\program Files\Microsoft Office\Templates\Presentation Designs 下面就可以了，然后你新建一个 ppt在幻灯片设计栏下方点预览导入你的母版就可以了或者直接打开下载的ppt模板，然后在模板里面新建就可以了。然后设计好ppt，另存为，如果制作一个ppt模板需要不同的模板，可以从下载的模板中复制到需要的模板中去。或者参考第一种方法。如下是详细内容： PPT模板如何用：学PowerPoint模板技巧 PowerPoint模板的应用可能不被人注意。如果能巧妙地利用PowerPoint模板，就可以为我们带来极大的方便，提升我们的工作效率。灵活调用模板 PowerPoint提供的模板非常丰富，可以根据需要灵活选用：选择“文件”→“新建”，在打开的任务窗格中可以看到它提供了“新建”、“根据现有演示文稿新建”和“根据模板新建”三种调用模板的方式。 “新建”下又有“根据设计模板”和“根据内容提示向导”等方式。而单击 “根据现有演示文稿新建”下的“选择演示文稿”，可以将现有演示文稿作为模板建立新文件。“根据模板新建”下则有“通用模板”和“https://www.doczj.com/doc/3516924096.html,上的模板”等多种选择，单击“通用模板”可以打开“模板” 1 对话框，选用系统安装的各种模板。网络模板上文已经做过介绍，这里不再重复。

史密斯圆图介绍

如何用史密斯圆图进行阻抗匹配！！ ---------------------------------------------------------------------------------------------- 史密斯圆图红色的代表阻抗圆，蓝色的代表导纳圆！！先以红色线为例！圆中间水平线是纯阻抗线，如果有点落在该直线上，表示的是纯电阻！！例如一个100欧的电阻，就在中间那条线上用红色标2.0的地方；15欧的电阻就落在中间红色标0.3的点上！水平线上方是感抗线，下方是容抗线；落在线上方的点，用电路表示，就是一个电阻串联一个电感，落在线下方的点，是一个电阻串联一个电容。图上的圆表示等阻抗线，落在圆上的点阻抗都相等，向上的弧线表示等感抗线，向下的弧线表示等容抗线！！

可以看出是感是容，是高是低接着讲蓝色线。因为导纳是阻抗的倒数，所以，很多概念都很相似。中间的是电导线，图上的圆表示等电导圆，向上的是等电纳线，向下的是等电抗线！用该图进行阻抗匹配计算的基本原则是：是感要补容，是容要加感，是高阻要想办法往低走，是低阻要想办法抬高。无论在任何位置，均要向50欧（中点）靠拢。进行匹配时候，在等阻抗圆以及等电导圆上进行换算。下图表示的是变化趋势！

以图上B点为例，如何进行阻抗匹配！！ B点所在位置为40+50j，先顺着等电导圆，运动到B1点，再顺着等阻抗圆，运行到终点（50欧）。按照上贴的运动规律，电路先并电容，再串电容。由此完成阻抗匹配。匹配方法讲完了，具体数值可通过RFSIM99计算！！再说点，S参数与SMITCH圆图的关系！！高频三极管，特别是上GHz的，一般都会列出一堆S参数。以下以C3355 400MHz时候S11参数为例，说明S参数和圆图的关系。频率|S11| 相位 400M 0.054 -77.0 根据S参数的定义可知，S11反射系数为0.054，也就是输入功率为1，则反射功率约为0.003。由于SMITCH图是反射系数的极坐标，因此，可用公式表示，

2020年史密斯圆图基本原理

作者：败转头作品编号44122544：GL568877444633106633215458 时间：2020.12.13 阻抗匹配与史密斯(Smith)圆图：基本原理摘要：本文利用史密斯圆图作为RF阻抗匹配的设计指南。文中给出了反射系数、阻抗和导纳的作图范例，并给出了MAX2474工作在900MHz时匹配网络的作图范例。事实证明，史密斯圆图仍然是确定传输线阻抗的基本工作。在处理RF系统的实际应用问题时，总会遇到一些非常困难的工作，对各部分级联电路的不同阻抗进行匹配就是其中之一。一般情况下，需要进行匹配的电路包括天线与低噪声放大器(LNA)之间的匹配、功率放大器输出(RFOUT)与天线之间的匹配、LNA/VCO输出与混频器输入之间的匹配。匹配的目的是为了保证信号或能量有效地从“信号源”传送到“负载”。在高频端，寄生元件(比如连线上的电感、板层之间的电容和导体的电阻)对匹配网络具有明显的、不可预知的影响。频率在数十兆赫兹以上时，理论计算和仿真已经远远不能满足要求，为了得到适当的最终结果，还必须考虑在实验室中进行的RF测试、并进行适当调谐。需要用计算值确定电路的结构类型和相应的目标元件值。有很多种阻抗匹配的方法，包括计算机仿真：由于这类软件是为不同功能设计的而不只是用于阻抗匹配，所以使用起来比较复杂。设计者必须熟悉用正确的格式输入众多的数据。设计人员还需要具有从大量的输出结果中找到有用数据的技能。另外，除非计算机是专门为这个用途制造的，否则电路仿真软件不可能预装在计算机上。手工计算：这是一种极其繁琐的方法，因为需要用到较长(“几公里”)的计算公式、并且被处理的数据多为复数。经验：只有在RF领域工作过多年的人才能使用这种方法。总之，它只适合于资深的专家。史密斯圆图：本文要重点讨论的内容。本文的主要目的是复习史密斯圆图的结构和背景知识，并且总结它在实际中的应用方法。讨论的主题包括参数的实际范例，比如找出匹配网络元件的数值。当然，史密斯圆图不仅能够为我们找出最大功率传输的匹配网络，还能帮助设计者优化噪声系数，确定品质因数的影响以及进行稳定性分析。

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