Kab lus no piav qhia txog 4 yam tseem ceeb ntawm RF circuits los ntawm plaub yam: RF interface, me me xav tau teeb liab, teeb liab cuam tshuam loj, thiab cuam tshuam los ntawm cov kab uas nyob ib sab, thiab muab cov ntsiab lus tseem ceeb uas xav tau tshwj xeeb hauv cov txheej txheem tsim PCB.
RF Circuit Court simulation ntawm lub interface ntawm RF
Wireless transmitter thiab receiver nyob rau hauv lub tswvyim, yuav muab faib ua ob feem ntawm lub hauv paus zaus thiab xov tooj cua zaus.Qhov tseem ceeb zaus muaj qhov ntau zaus ntawm cov teeb liab tawm tswv yim ntawm lub transmitter thiab qhov ntau zaus ntawm cov teeb liab tso tawm ntawm lub receiver.Lub bandwidth ntawm lub hauv paus zaus txiav txim siab tus nqi pib uas cov ntaub ntawv tuaj yeem ntws hauv qhov system.Qhov tseem ceeb zaus yog siv los txhim kho kev ntseeg siab ntawm cov ntaub ntawv ntws thiab txo cov load los ntawm lub transmitter ntawm qhov nruab nrab kis ntawm tus nqi muab cov ntaub ntawv.Yog li ntawd, PCB tsim ntawm lub hauv paus zaus Circuit Court yuav tsum muaj kev paub dav ntawm teeb liab ua engineering.Lub RF circuitry ntawm lub transmitter converts thiab upscales cov txheej txheem tseem ceeb zaus teeb liab mus rau ib tug tshwj xeeb channel thiab txhaj cov teeb liab no rau hauv nruab nrab kis tau tus mob.Conversely, tus receiver's RF circuitry tau txais lub teeb liab los ntawm kev sib kis xov xwm thiab hloov thiab downscales nws mus rau qhov tseem ceeb zaus.
Transmitters muaj ob lub hom phiaj tseem ceeb ntawm PCB tsim: thawj yog tias lawv yuav tsum xa cov hwj chim tshwj xeeb thaum siv lub zog tsawg kawg nkaus.Qhov thib ob yog tias lawv tsis tuaj yeem cuam tshuam nrog kev ua haujlwm ib txwm muaj ntawm transceiver hauv cov kab uas nyob ib sab.Nyob rau hauv cov nqe lus ntawm lub receiver, muaj peb lub hom phiaj tseem ceeb ntawm PCB tsim: ua ntej, lawv yuav tsum raug kho kom raug me me teeb liab;thib ob, lawv yuav tsum muaj peev xwm tshem tawm cov teeb meem cuam tshuam sab nraud ntawm qhov xav tau channel;qhov kawg taw tes yog tib yam li lub transmitter, lawv yuav tsum haus tsawg zog.
RF Circuit Court simulation ntawm cov teeb liab cuam tshuam loj
Cov neeg txais yuav tsum tau nkag siab rau cov teeb liab me me, txawm tias thaum muaj kev cuam tshuam loj (blockers) muaj nyob.Qhov xwm txheej no tshwm sim thaum sim kom tau txais qhov tsis muaj zog lossis nyob deb xaim hluav taws xob nrog lub zog xa hluav taws xob tshaj tawm hauv cov channel uas nyob ze.Lub teeb liab cuam tshuam tuaj yeem yog 60 txog 70 dB loj dua li qhov xav tau teeb liab thiab tuaj yeem thaiv qhov kev txais tos ntawm lub teeb liab ib txwm nyob rau theem ntawm lub receiver nrog ntau qhov kev pab cuam lossis los ntawm kev ua rau lub receiver ua kom muaj suab nrov ntau hauv lub input theem.Ob qhov teeb meem uas tau hais los saum toj no tuaj yeem tshwm sim yog tias tus txais, nyob rau hauv theem kev nkag, yog tsav mus rau hauv cheeb tsam ntawm nonlinearity los ntawm qhov kev cuam tshuam.Txhawm rau zam cov teeb meem no, qhov kawg ntawm lub receiver yuav tsum yog linear heev.
Yog li ntawd, "linearity" kuj yog ib qho tseem ceeb rau kev txiav txim siab thaum tsim tus txais PCB.Raws li lub receiver yog ib tug nqaim-band circuit, yog li cov nonlinearity yog los ntsuas qhov "intermodulation distortion (intermodulation distortion)" rau cov txheeb cais.Qhov no suav nrog siv ob lub sine lossis cosine nthwv dej ntawm cov zaus sib xws thiab nyob hauv nruab nrab band (hauv band) los tsav lub teeb liab tawm tswv yim, thiab tom qab ntawd ntsuas cov khoom ntawm nws qhov kev cuam tshuam cuam tshuam.Los ntawm thiab loj, SPICE yog lub sijhawm siv sijhawm thiab kim software simulation vim tias nws yuav tsum ua ntau lub voj voog ua ntej nws tuaj yeem tau txais qhov xav tau kev daws teeb meem kom nkag siab qhov cuam tshuam.
RF Circuit Court simulation ntawm cov teeb liab me me xav tau
Lub receiver yuav tsum tau rhiab heev los mus ntes me me input signals.Feem ntau, lub zog nkag ntawm lub receiver tuaj yeem ua me me li 1 μV.qhov rhiab heev ntawm lub receiver yog txwv los ntawm lub suab nrov generated los ntawm nws input circuit.Yog li ntawd, suab nrov yog qhov tseem ceeb thaum tsim ib lub receiver rau PCB.Tsis tas li ntawd, muaj peev xwm los kwv yees lub suab nrov nrog cov cuab yeej simulation yog qhov tseem ceeb.Daim duab 1 yog ib tug raug superheterodyne (superheterodyne) txais.Lub teeb liab tau txais yog thawj zaug lim thiab tom qab ntawd cov teeb liab tawm tswv yim yog amplified nrog lub suab nrov qis (LNA).Thawj lub zos oscillator (LO) yog siv los sib tov nrog cov teeb liab no los hloov cov teeb liab no mus rau qhov nruab nrab zaus (IF).Pem hauv ntej-kawg (pem hauv ntej-kawg) Circuit Court suab nrov yog nyob ntawm LNA, tov khoom (sib tov) thiab LO.Txawm hais tias siv cov suab nrov SPICE raws li kev txheeb xyuas, koj tuaj yeem nrhiav LNA suab nrov, tab sis rau cov khoom sib tov thiab LO, nws tsis muaj txiaj ntsig, vim tias lub suab nrov hauv cov blocks no yuav yog lub teeb liab LO loj heev.
Lub teeb liab me me xav kom tus txais yuav tsum tau ua kom nrov heev, feem ntau yuav tsum tau nce siab li 120 dB.Ntawm qhov kev nce siab zoo li no, txhua lub teeb liab sib txuas los ntawm cov zis (cov khub niam txiv) rov qab mus rau cov tswv yim tuaj yeem tsim teeb meem.Qhov laj thawj tseem ceeb ntawm kev siv lub super outlier receiver architecture yog tias nws tso cai rau qhov nce tau muab faib ua ntau zaus kom txo tau txoj hauv kev sib txuas.Qhov no kuj ua rau thawj LO zaus txawv ntawm qhov input signal zaus, tuaj yeem tiv thaiv kev cuam tshuam loj "kev ua qias tuaj" rau lub teeb liab me me.
Rau cov laj thawj sib txawv, hauv qee qhov kev sib txuas lus wireless, kev hloov pauv ncaj qha (kev hloov pauv ncaj qha) lossis kev sib txawv sab hauv (homodyne) architecture tuaj yeem hloov pauv qhov sib txawv ntawm sab nraud.Nyob rau hauv no architecture, RF input teeb liab yog ncaj qha hloov mus rau lub hauv paus zaus nyob rau hauv ib kauj ruam, yog li ntawd feem ntau ntawm qhov nce yog nyob rau hauv lub hauv paus zaus thiab LO yog nyob rau tib zaus raws li lub input teeb liab.Hauv qhov no, qhov cuam tshuam ntawm qhov sib txuas me me yuav tsum tau nkag siab thiab cov qauv ntxaws ntawm "txoj kev teeb liab" yuav tsum tau tsim, xws li: kev sib txuas los ntawm cov substrate, coupling ntawm pob hneev taw thiab cov kab solder (bondwire) , thiab coupling los ntawm lub hwj chim kab coupling.
RF Circuit Court Simulation ntawm Adjacent Channel cuam tshuam
Distortion kuj plays lub luag haujlwm tseem ceeb hauv lub transmitter.Lub nonlinearity generated los ntawm lub transmitter nyob rau hauv cov zis Circuit Court tej zaum yuav ua rau lub zaus dav ntawm lub teeb liab kis tau tus mob mus rau kis thoob plaws cov nyob ib sab channel.Qhov tshwm sim no hu ua "spectral regrowth".Ua ntej lub teeb liab mus txog lub transmitter lub hwj chim amplifier (PA), nws bandwidth yog txwv;Txawm li cas los xij, "intermodulation distortion" hauv PA ua rau bandwidth nce ntxiv.Yog hais tias lub bandwidth nce ntau dhau lawm, lub transmitter yuav tsis muaj peev xwm ua tau raws li qhov xav tau ntawm lub zog ntawm nws cov neeg nyob sib ze.Thaum xa cov teeb liab hloov pauv digital, nws yog qhov ua tsis tau zoo los kwv yees qhov rov loj hlob ntawm spectrum nrog SPICE.Vim hais tias txog 1000 cov cim digital (cim) ntawm kev ua haujlwm sib kis yuav tsum tau simulated kom tau txais tus neeg sawv cev spectrum, thiab tseem yuav tsum tau sib txuas cov neeg nqa khoom siab, cov no yuav ua rau SPICE kev tsom xam tsis zoo.
Lub sij hawm xa tuaj: Mar-31-2022