Data Sheet

FSC‐BW226Datasheet
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 ShenzhenFeasycomTechnologyCo.,Ltd.www.feasycom.com
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 9.2LayoutGuidelines(InternalAntenna)
Itisstronglyrecommendedtousegoodlayoutpracticestoensureproperoperationofthemodule.Placingcopperor
anymetalnearantennadeterioratesitsoperationbyhavingeffectonthematchingproperties.Metalshieldaroundthe
antenna will prevent the radiation and thus metal case should not be used with
 the module. Use grounding vias
separated max3mm apart at the edge ofgroundingareasto preventRFpenetratinginside the PCB andcausing an
unintentional resonator.UseGNDviasallaroundthePCBedges.
Themotherboardshouldhavenobareconductorsorviasinthisrestrictedarea,
becauseitisnotcoveredbystopmask
print.Alsonocopper(planes,tracesorvias)areallowedinthisarea,becauseofmismatchingtheon‐boardantenna.
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Figure13:FSC‐BW226RestrictedArea
FollowingrecommendationshelpstoavoidEMCproblemsarisinginthedesign.Notethateachdesignisuniqueandthe
followinglistdonotconsiderallbasicdesignrulessuchasavoidingcapacitivecouplingbetweensignallines.Following
listisaimedtoavoidEMCproblemscausedbyRFpartofthe
module.Usegoodconsiderationtoavoidproblemsarising
fromdigitalsignalsinthedesign.
Ensurethatsignallineshavereturnpathsasshortaspossible.Forexampleifasignalgoestoaninnerlayerthrougha
via, always use ground vias around it. Locate them tightly and symmetrically around the
 signal vias. Routing of any
sensitivesignalsshouldbedoneintheinnerlayersofthePCB.Sensitivetracesshouldhaveagroundareaaboveand
under the line. If this is not possible, make sure that the return path is short by other means (for example using a
ground
linenexttothesignalline).
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 9.3LayoutGuidelines(ExternalAntenna)
Placementand PCB layoutarecritical to optimize theperformancesofa module without on‐boardantenna designs.
Thetracefromtheantennaportofthemoduletoanexternalantennashouldbe50andmustbeasshortaspossible
toavoidanyinterferenceintothetransceiverofthe
module.ThelocationoftheexternalantennaandRF‐INportof
themodule shouldbe kept awayfromanynoise sourcesand digital traces.Amatchingnetworkmightbeneeded in
betweentheexternalantennaandRF‐INporttobettermatchtheimpedancetominimizethereturnloss.