an5142 link budget

12
RF System (Link Budget) Calculations System Variables Variable Units Equation Frequency MHz Speed of Light c m/s Wavelength λ m Block Variable Units Equation PA Power dBm TX Match Loss dB TX source dBm TX connector loss dB (from Connector Loss sheet) TX cable loss dB (from Cable Loss sheet) TX connector loss (remote antenna) dB (from Connector Loss sheet) TX power dBm TX antenna gain dBi Effective (Isotropic) Radiated Power EIRP dBm Distance d m Channel Medium Loss Factor dB (from Medium Loss sheet) Free Space Loss dB Power at RX Antenna, Free Space Path dB Flat Earth Loss (Includes Ground Boun dB (from Ground Multipath sheet) Multipath Loss dB Obstruction Loss dB Power at RX Antenna, Flat Earth Path dB RX antenna gain dBi RX connector loss dB RX cable loss dB RX connector loss (remote antenna) dB RX power, Free Space Path dBm RX power, Flat Earth Path dBm Receiver Sensitivity Calculations Variable Units Equation RX Noise Figure NF dB Operating Temperature K f0 λ = c/f0 PPA LMatchT PTX LConT1 LCabT LConT2 PT PT = PTX(C&C Loss) GT EIRP = PT GT L0 LFS LFS = (λ/4πd) 2 PChanFS PChanFS = LFSL0 EIRP LFE LMP LObs-Total PChanFE PChanFE = LFEL0LMPLObs EIRP GR LConR1 LCabR LConR2 PRFS PRFS = PChanFS GR(C&C Loss) PRFE PRFE = PChanFE GR(C&C Loss) T0

Upload: phuonglanbui

Post on 16-Nov-2015

32 views

Category:

Documents


10 download

DESCRIPTION

AN5142 Link Budget

TRANSCRIPT

Link BudgetRF System (Link Budget) CalculationsSystem VariablesVariableUnitsEquationValueFrequencyf0MHz315Speed of Lightcm/s299792458Wavelengthm = c/f00.9517220889BlockVariableUnitsEquationValuePA PowerPPAdBm10TX Match LossLMatchTdBTX sourcePTXdBm10TX connector lossLConT1dB(from Connector Loss sheet)-0.57TX cable lossLCabTdB(from Cable Loss sheet)TX connector loss (remote antenna)LConT2dB(from Connector Loss sheet)TX powerPTdBmPT = PTX(C&C Loss)9.43TX antenna gainGTdBi-15Effective (Isotropic) Radiated PowerEIRPdBmEIRP = PT GT-5.57Distancedm175Channel Medium Loss FactorL0dB(from Medium Loss sheet)0Free Space LossLFSdBLFS = (/4d)2-67.2747552714Power at RX Antenna, Free Space PathPChanFSdBPChanFS = LFSL0 EIRP-72.8447552714Flat Earth Loss (Includes Ground Bounce)LFEdB(from Ground Multipath sheet)-92.734165755Multipath LossLMPdBObstruction LossLObs-TotaldB0Power at RX Antenna, Flat Earth PathPChanFEdBPChanFE = LFEL0LMPLObs EIRP-98.304165755RX antenna gainGRdBi-15RX connector lossLConR1dB-0.57RX cable lossLCabRdBRX connector loss (remote antenna)LConR2dBRX power, Free Space PathPRFSdBmPRFS = PChanFS GR(C&C Loss)-88.4147552714RX power, Flat Earth PathPRFEdBmPRFE = PChanFE GR(C&C Loss)-113.874165755-114Sensitivity of RxReceiver Sensitivity CalculationsVariableUnitsEquationValueRX Noise FigureNFdB7Operating TemperatureT0K290Effective Noise TemperatureTeKTe = T0(NF - 1)1163.4429775191Boltzmann's constantkJ/K1.38E-23Receive BandwidthBWRXMHz0.012Antenna TemperatureTAntK300Noise Power (at RX)PndBmPn = k(TAnt + Te)BWRX-126.1556386257Signal to Noise RatioSNRRXdBSNRRX = PRX/Pn12.1556386257

Link PlotLink PlotDevice Sensitivity-114Signal PathSensitivityTX10-114TX Ant-5.57-114RX Ant-98.304165755-114RX-113.874165755-114Maxim TXSupply (V)PA OutputMaxim RXFrequency (MHz)ModulationSensitivity (dBm)MAX14722.16MAX1470315ASK-1092.710.3433.92ASK-1043.613.7MAX1471315ASK-114MAX14792.15.3315FSK-1082.710433.92ASK-1143.612.2433.92FSK-108MAX70302.16.7MAX1473315ASK-1143.613.1433.92ASKMAX70312.16.7MAX7030315ASK-1143.613.1433.92ASK-113MAX70322.16.7MAX7031315FSK-1103.613.1433.92FSK-107MAX70442.19MAX7032315ASK-1142.712.5433.92ASK-1133.615.8315FSK-110MAX70492.115433.92FSK-1073.615MAX7033315ASK-114MAX70572.15.2433.92ASK3.612.6MAX7034315ASK-114MAX70582.15.9433.92ASK-1133.613.3MAX7036315ASK-109MAX70602.114.5433.92ASK-1073.614.5MAX7042315FSK-110433.92FSK-109All numbers are based on Datasheet conditionsAll numbers are based on Datasheet conditions

Link Plot

-114

Ground MultipathGround Multipath LossReference Maxim Application Note AN3586Ground Reflection Path LossSystem VariablesVariableUnitsEquationValueTX heighthTXm1RX heighthRXm1Distancedm(from Link Budget sheet)175Direct Pathd1md1 = (d2+(hTX-hRX)2)1/2175Reflection Pathd2md2 = (d2+(hTX+hRX)2)1/2175.0114281983Reflection Path dmd = d2 - d10.0114281983Distance IndexDistanceDelta dFree Space LossEst. Flat Earth LossExact Flat Earth LossEstimated Reflection Path demde = 2hTXhRX/d0.011428571402.00.8284271247-28.434594211-15.0514997832-33.4737222587Wavelengthm(from Link Budget sheet)0.951722088912.10.8027964634-28.8164764111-15.8152641835-32.3267052015Normalized Ground Bounce Amplitudeanone122.20.7763802081-29.2144139298-16.6111392209-31.4441088394Loss From Ground Bounce CancellationLGBdBLGB =10log10(0.5(1+a2-2acos(2d/)))-25.459410483632.30.7492653629-29.6283180087-17.4389473786-30.7750446287Free Space LossLFSdBLFS = 10log10(/4d)2-67.274755271442.40.7215515921-30.0580421642-18.2983956897-30.2863347506Flat Earth LossLFEdBLFE = LGB+ LFS-92.73416575552.50.6933500628-30.5033843116-19.1890799844-29.955171855262.70.6647818157-30.9640896458-20.1104906529-29.7651266863Ground Reflection Path Loss Approximation (for d > 5(hTX+hRX))72.80.6359756965-31.4398541957-21.0620197526-29.7038189275System VariablesVariableUnitsEquationValue83.00.6070659151-31.930328946-22.0429692532-29.7614841146Estimated Flat Earth Loss*LFEedBLFEe = 10log10(hTX2hRX2/2d4)-92.731821904193.20.5781893316-32.4351244153-23.0525601918-29.9300572795Estimated Ground Bounce Cancellation LossLGBedB= LFEe - LFS-25.4570666327103.40.5494825907-32.9538155667-24.0899424948-30.2025726944113.60.5210792433-33.4859469301-25.1542052214-30.5727671687* Introduction to RF Propagation, John S. Seybold, p.172123.80.4931069943-34.0310378149-26.244386991-31.0348201298134.10.4656852105-34.588587504-27.3594863693-31.583188556144.30.4389227967-35.1580803259-28.4984720131-32.2125088501154.60.4129165224-35.7389905182-29.6602923978-32.9175459958165.00.3877498439-36.3307868107-30.8438849827-33.6931755002175.30.3634922335-36.9329366697-32.0481847006-34.534387085185.70.3401989924-37.5449101635-33.2721316882-35.4363016376196.10.3179115013-38.1661834213-34.5146782039-36.3941949372206.60.2966578396-38.7962416726-35.7747947065-37.403523348217.10.2764536971-39.4345818654-37.0514750922-38.4599480745227.60.2573034975-40.0807148728-38.3437411069-39.5593557633238.20.2392016559-40.7341673032-39.6506459676-40.6978741882248.90.2221339023-41.3944829386-40.9712772384-41.8718825127259.60.2060786116-42.0612238284-42.3047590181-43.07801616952610.40.1910080942-42.7339710689-43.650253499-44.31316677912711.20.1768898115-43.412325301-45.0069619632-45.57447775872812.10.1636874933-44.0959069597-46.3741252807-46.85933638372913.10.1513621432-44.7843563065-47.7510239743-48.16536309393014.20.1398729239-45.4773332765-49.1369779143-49.49039879873115.40.1291779242-46.1745171695-50.5313457003-50.83249086343216.70.1192348105-46.8756062122-51.9335237858-52.18987836383318.10.1100013702-47.5803170163-53.342945394-53.56097709573419.70.1014359573-48.288383955-54.7590792713-54.94436472673521.30.0934978478-48.9995584775-56.1814283163-56.33876638383623.20.0861475192-49.7136083795-57.6095281203-57.74304089143725.20.0793468606-50.4303170441-59.0429454495-59.1561678043827.30.0730593259-51.1494826666-60.4812766945-60.57723532253929.70.067250037-51.8709174736-61.9241463085-62.00542913674032.30.0618858475-52.5944469461-63.3712052534-63.44002220274135.10.0569353715-53.319909053-64.8221294673-64.88036543854238.20.0523689865-54.0471535028-66.2766183669-66.32587930084341.50.0481588131-54.7760410157-67.7343933927-67.77604619584445.10.0442786792-55.5064426221-69.1951966056-69.23040366884549.10.04070407-56.2382389886-70.6587893384-70.68853831034653.40.0374120692-56.9713197735-72.1249509083-72.15008032134758.20.0343812925-57.7055830145-73.5934773904-73.61469867374863.30.0315918173-58.4409345465-75.0641804543-75.08209681144968.90.029025109-59.1772874517-76.5368862647-76.55200883455075.00.0266639468-59.9145615416-78.0114344444-78.02419611815181.60.0244923486-60.6526828687-79.4876770987-79.49844431625288.90.0224954974-61.3915832697-80.9654779007-80.97456070995396.80.0206596695-62.1311999364-82.444711234-82.452371859354105.40.0189721643-62.8714750152-83.9252613917-83.931721525655114.80.0174212373-63.6123552338-85.4070218289-85.412468831156125.00.0159960352-64.3537915523-86.8898944658-86.894486629457136.20.0146865352-65.0957388395-88.3737890402-88.37766006158148.30.0134834861-65.8381555715-89.8586225042-89.861885272859161.60.0123783539-66.5810035522-91.3443184657-91.347068281160175.00.0114281983-67.2747552714-92.7318219041-92.734165755

Ground Multipath

Free Space LossEst. Flat Earth LossExact Flat Earth Loss

Cable LossCable LossSystem VariablesVariableUnitsEquationValueCable Type@1GHzPasternack Enterprisese, Catalog 2008B, p254-256Attenuation at 1GHzGCab1GdB/100 ft-20RG-58C/U-20Length of CabledCabm0.61RG-142B/U-13Cable Loss FactorLcabdB-0.4002624672RG-174A/U-31RG-8X-13.52ft = 0.6096m

Range (meters)Path Loss (dB)

ObstructionsObstructions LossBlockVariableUnitsEquationValueFirst Obstruction LossLObs1dB0.0Second Obstruction LossLObs2dB0.0Third Obstruction LossLObs3dB0.0Fourth Obstruction LossLObs4dB0.0Fifth Obstruction LossLObs5dB0.0Total Obstruction LossLObs-TotaldB0.0ObstructionLoss FigureInterior Wall3.0dBExterior Wall10.0dBWindow2.0dBElectronic Design - Top 5 Engineering Essentials, Louis E. Frenzel, 2011 Penton, p.5Light Internal Wall (plaster board), Window3.4dBConcrete or Brick Internal Wall6.9dBFloor (reinforced concrete