Eli nqaku lichaza iimpawu ezi-4 ezisisiseko zeesekethe ze-RF kwiinkalo ezine: ujongano lweRF, umqondiso omncinci olindelekileyo, umqondiso omkhulu wokuphazamiseka, kunye nokuphazamiseka okuvela kwiitshaneli ezikufutshane, kwaye inika izinto ezibalulekileyo ezifuna ingqalelo ekhethekileyo kwinkqubo yoyilo lwePCB.
Ukulinganisa kwe-RF yesekethe yojongano lweRF
Isidluliseli esingenacingo kunye nomamkeli kumbono, sinokwahlulwa sibe ziinxalenye ezimbini zefrikhwensi esisiseko kunye nefrikhwensi yerediyo.I-frequency esisiseko iqulethe uluhlu lwamafrikhwensi omqondiso wegalelo le-transmitter kunye noluhlu lwefrikhwensi yomqondiso wesiphumo somamkeli.I-bandwidth ye-frequency esisiseko imisela isantya esisisiseko apho idatha inokuhamba khona kwinkqubo.I-frequency esisiseko isetyenziselwa ukuphucula ukuthembeka kokuhamba kwedatha kunye nokunciphisa umthwalo obekwe ngumthumeli kwi-transmitter medium kwizinga elinikiweyo ledatha.Ke ngoko, uyilo lwePCB yesekethe esisiseko yesekethe ifuna ulwazi olubanzi lobunjineli bokwenza umqondiso.I-RF yesekethe ye-transmitter iguqula kwaye inyuse isignali yefrikhwensi esetyenzisiweyo kwitshaneli echaziweyo kwaye ifaka lo mqondiso kwindawo yothumelo.Ngokwahlukileyo, i-RF yesekethe ye-RF ifumana isignali kwimidiya yothumelo kwaye iyiguqule kwaye ithobe kwi-frequency esisiseko.
Abadlulisi baneenjongo ezimbini eziphambili zoyilo lwePCB: eyokuqala kukuba kufuneka bagqithise isixa esithile samandla ngelixa besebenzisa ubuncinci bamandla anokwenzeka.Okwesibini kukuba abanako ukuphazamisa ukusebenza okuqhelekileyo kwe-transceiver kumajelo akufutshane.Ngokommkeli, kukho iinjongo ezintathu eziphambili zePCB: okokuqala, kufuneka babuyisele ngokuchanekileyo iimpawu ezincinci;okwesibini, kufuneka bakwazi ukususa imiqondiso yokuphazamiseka ngaphandle kwejelo elifunwayo;inqaku lokugqibela liyafana nesithumeli, kufuneka basebenzise amandla amancinci kakhulu.
Ukulinganisa kwe-RF yesekethe yeempawu ezinkulu eziphazamisayo
Abamkeli kufuneka babe novelwano kwiimpawu ezincinci, nangona iimpawu ezinkulu eziphazamisayo (i-blockers) zikhona.Le meko ivela xa uzama ukufumana isignali ebuthathaka okanye ekude yokuhambisa i-transmitter yosasazo olunamandla kwijelo elikufutshane elikufutshane.Isiginali ephazamisayo inokuba yi-60 ukuya kwi-70 dB enkulu kunesiginali elindelekileyo kwaye inokuthintela ukwamkelwa kwesiginali eqhelekileyo kwinqanaba lokufaka ummkeli ngomthamo omkhulu wokugubungela okanye ngokubangela ukuba umamkeli enze ingxolo egqithisileyo isigaba sokungena.Ezi ngxaki zimbini zikhankanywe ngasentla zinokuthi zenzeke ukuba ummkeli, kwinqanaba lokufaka, uqhutyelwa kummandla wokungahambelani nomthombo wokuphazamiseka.Ukunqanda ezi ngxaki, isiphelo sangaphambili somamkeli kufuneka sibe simgca kakhulu.
Ngoko ke, "umgca" ikwayinto ebalulekileyo yokuqwalaselwa xa uyila i-PCB yomamkeli.Njengoko i-receiver i-circuit-band yesekethe, ngoko ke ukungahambelani kukulinganisa "i-intermodulation distortion (i-intermodulation distortion)" kwizibalo.Oku kubandakanya ukusebenzisa i-sine okanye amaza e-cosine amaza afanayo kwaye abekwe kumbindi webhendi (kwibhendi) ukuqhuba umqondiso wokufakwayo, kwaye emva koko ukulinganisa imveliso yokuphazamiseka kwayo kwe-intermodulation.Ngokubanzi, i-SPICE yisoftware yokulinganisa ethatha ixesha kwaye ixabisa kakhulu kuba kufuneka yenze imijikelo emininzi phambi kokuba ifumane isisombululo esifunekayo sokuqonda ukugqwetheka.
Ukulinganisa kwe-RF yesekethe yomqondiso omncinci ofunekayo
Umamkeli kufuneka abe novakalelo kakhulu ekubhaqeni imiqondiso emincinci yegalelo.Ngokubanzi, amandla egalelo lomamkeli anokuba yincinci njenge-1 μV.ubuntununtunu bomamkeli bukhawulelwe yingxolo eyenziwe yisekethe yegalelo layo.Ngoko ke, ingxolo ibalulekile ingqalelo xa uyila umamkeli PCB.Ngaphezu koko, ukubanakho ukuqikelela ingxolo ngezixhobo zokulinganisa kubalulekile.Umzobo we-1 ngumamkeli oqhelekileyo we-superheterodyne (superheterodyne).Umqondiso ofunyenweyo uqala ukuhluzwa kwaye emva koko umqondiso wegalelo ukhuliswe ngesandisi-lizwi esisezantsi (LNA).I-oscillator yokuqala yendawo (LO) isetyenziselwa ukuxuba kunye nesi siginali ukuguqula lo mqondiso kwi-frequency intermediate (IF).Isiphelo sangaphambili (isiphelo sangaphambili) ukusebenza kwengxolo yesiphaluka kuxhomekeke ikakhulu kwi-LNA, i-mixer (i-mixer) kunye ne-LO.nangona ukusetyenziswa kohlalutyo lwengxolo ye-SPICE eqhelekileyo, unokukhangela ingxolo ye-LNA, kodwa kumxube kunye ne-LO, akunamsebenzi, kuba ingxolo kulezi zibhloko, iya kuba yi-LO isignali enkulu kakhulu echaphazelekayo.
Isignali encinci yegalelo ifuna ukuba umamkeli akhuliswe ngokugqithisileyo, ngokuqhelekileyo efuna inzuzo ephezulu njenge-120 dB.Kwinzuzo ephezulu ngolo hlobo, naluphi na umqondiso odityaniswe kwimveliso (izibini) ubuyela kwigalelo unokudala iingxaki.Isizathu esibalulekileyo sokusebenzisa i-architecture ye-super outlier receiver kukuba ivumela inzuzo ukuba isasazwe kwiifrikhwensi ezininzi ukunciphisa ithuba lokudibanisa.Oku kwakhona kwenza ukuba i-LO yokuqala i-frequency ihluke kwi-frequency ye-input signal, inokuthintela isignali enkulu yokuphazamiseka "ungcoliseko" kwisignali encinci yokufaka.
Ngezizathu ezahlukeneyo, kwezinye iinkqubo zonxibelelwano ezingenazingcingo, ukuguqulwa ngokuthe ngqo (ukuguqulwa ngokuthe ngqo) okanye ukwahluka kwangaphakathi (i-homodyne) i-architecture inokutshintsha indawo ye-ultra-outer differential architecture.Kolu lwakhiwo, umqondiso we-RF wegalelo uguqulelwa ngokuthe ngqo kwi-frequency esisiseko kwinyathelo elinye, ukuze uninzi lwenzuzo ikwi-frequency esisiseko kwaye i-LO ikwi-frequency efanayo ne-input signal.Kule meko, impembelelo yexabiso elincinci lokudibanisa kufuneka iqondwe kwaye imodeli ecacileyo "yendlela yesignali elahlekileyo" kufuneka isungulwe, njengokuba: ukudibanisa nge-substrate, ukudibanisa phakathi kwepakethe yephakheji kunye nomgca we-solder (bondwire) , kunye nokudibanisa ngokusebenzisa ukudibanisa intambo yombane.
Ukulinganisa kwe-RF yeSekethe ye-Adjacent Channel Interference
Ukugqwetheka kukwadlala indima ebalulekileyo kwi-transmitter.I-nonlinearity eyenziwa yi-transmitter kwi-output circuit inokubangela ukuba ububanzi befrikhwensi yesiginali edluliselweyo isasazeke kumajelo akufutshane.Le nto ibizwa ngokuba "yi-spectral regrowth".Ngaphambi kokuba umqondiso ufikelele kwi-amplifier yamandla yokudlulisa (PA), i-bandwidth yayo ilinganiselwe;nangona kunjalo, "ukuphazamiseka kwe-intermodulation" kwi-PA kubangela ukuba i-bandwidth inyuke kwakhona.Ukuba i-bandwidth inyuka kakhulu, i-transmitter ayiyi kukwazi ukuhlangabezana neemfuno zamandla amajelo angabamelwane.Xa usasaza isiginali yokumodareyitha yedijithali, akunakwenzeka ukuqikelela ukukhula kwakhona kwesspectrum nge-SPICE.Ngenxa yokuba iisimboli zedijithali ezimalunga ne-1000 (umqondiso) womsebenzi wothumelo kufuneka zifaniswe ukufumana i-spectrum emeleyo, kwaye kufuneka kwakhona ukudibanisa i-carrier ye-frequency ephezulu, ezi ziza kwenza uhlalutyo lwe-SPICE oludlulayo lube lungenakwenzeka.
Ixesha lokuposa: Mar-31-2022