电线基本常识

2009-3-191„„„„2009-3-192„„„„,120135,,,0.3~25µ120~135.,0.6~0.8µ,,,(porous)3.2~4.51.0~1.3µ,a),,200,350,a),,b),,,,,,,RedPlague,,,,,,-2009-3-193„„„„„„„„„„„2009-3-194„„„„„2009-3-195„„„„„„105PVCPEPPPFAFEPETFE20243424.5~29.42042~49200250200350~450300~4002002002502003504503004002008x10151x10171x10171x10181x10181x10165.02.322.222.12.12.60.100.00020.00030.00020.00030.000810590-260205150-15-6510-180-80-652009-3-196,,,,,1kMk,1km,M-km,,,,,10~20,,,,,,.,,2009-3-197CE,,,I090º,,90º90º,,I0I0Ww,Ev,f(Hz),ω2πf,C(F),θW=Eicosθ=E2ωCcosθθ=90ºCcosθ=tan(º-θ)W=E2ωCtanωtantantanω,2009-3-198TP:TwistedPairwire,,,22~2622~26,,,38.1cm14cm,,12.7cm,,,UTP:UnshildedTwistedPairSTP:ShieldedTwistedPair.,,,,,,,100Mbps~155Mbps,,,,,,100155Mbps.,,1.,,2.3.2009-3-1994.,2.EIA/TIA1,214b21MHz4Mbps4Mbps3ANSIEIA/TIA56816MH3ANSIEIA/TIA56816MHz,10Mbps10base-T420MHz,16Mbps,10base-T/100base-T.5,,100MHz100Mbps,100base-T10base-T,100Mbps,100baseT10baseT,1001502009-3-19103.,,1Attenuation,,dB”,,,2FEXT,NEXTFEXTENXTUTPUTPNEXTNEXT40NEXT40NEXTNEXTNEXT30.141~100MHz1001201505ACRACRSNR:Signa1-gNoiceratioNEXTACR106SNRSNR2009-3-1911SNR.