Lesi sihloko sichaza izici eziyisisekelo ezingu-4 zamasekhethi e-RF ezicini ezine: isixhumi esibonakalayo se-RF, isignali encane elindelekile, isignali enkulu yokuphazamiseka, nokuphazamiseka okuvela eziteshini eziseduze, futhi inikeza izici ezibalulekile ezidinga ukunakwa okukhethekile enqubweni yokuklama ye-PCB.
Ukulingiswa kwesekethe ye-RF ye-interface ye-RF
I-Wireless Transmitter nomamukeli kumqondo, ingahlukaniswa izingxenye ezimbili zefrikhwensi eyisisekelo kanye nefrikhwensi yomsakazo.Ifrikhwensi eyisisekelo iqukethe ububanzi befrikhwensi yesiginali yokufaka yesidlulisi kanye nobubanzi befrikhwensi yesiginali yokuphumayo yomamukeli.I-bandwidth yefrikhwensi eyisisekelo inquma izinga eliyisisekelo idatha engageleza ngayo ohlelweni.Imvamisa eyisisekelo isetshenziselwa ukuthuthukisa ukuthembeka kokugeleza kwedatha kanye nokunciphisa umthwalo obekwe umthumeli endaweni yokudlulisela ngenani ledatha elinikeziwe.Ngakho-ke, idizayini ye-PCB yesekethe yemvamisa eyisisekelo idinga ulwazi olubanzi lobunjiniyela bokucubungula isignali.Umjikelezo we-RF we-transmitter uguqula futhi ukhuphule isignali yefrikhwensi eyisisekelo ecutshunguliwe esiteshini esicacisiwe bese ijova lesi siginali endaweni yokudlulisela.Ngokuphambene, i-RF circuitry yomamukeli ithola isignali kumidiya yokudlulisela futhi iyiguqule futhi yehliselwe kufrikhwensi eyisisekelo.
Ama-Transmitter anezinhloso ezimbili eziyinhloko zokuklama i-PCB: eyokuqala ukuthi kufanele adlulisele inani elithile lamandla kuyilapho esebenzisa inani elincane lamandla angenzeka.Okwesibili ukuthi abakwazi ukuphazamisa ukusebenza okuvamile kwe-transceiver eziteshini eziseduze.Ngokomamukeli, kunezinhloso ezintathu eziyinhloko zokuklama i-PCB: okokuqala, kufanele zibuyisele ngokunembile izimpawu ezincane;okwesibili, kufanele bakwazi ukususa izimpawu zokugxambukela ngaphandle kwesiteshi abasifunayo;iphuzu lokugcina lifana ne-transmitter, kumele badle amandla amancane kakhulu.
Ukulingisa kwesekhethi ye-RF yamasignali amakhulu aphazamisayo
Abamukeli kufanele bazwele kumasignali amancane, ngisho nalapho amasignali amakhulu aphazamisayo (ama-blockers) ekhona.Lesi simo sivela lapho uzama ukuthola isignali yokudlulisa ebuthakathaka noma ekude enomsakazo onamandla osakaza esiteshini esiseduze.Isiginali ephazamisayo ingaba nkulu ngo-60 kuye ku-70 dB kunesiginali elindelekile futhi ingavimba ukwamukelwa kwesiginali evamile esigabeni sokufaka somamukeli ngenani elikhulu lokumboza noma ngokubangela ukuthi umamukeli akhiphe inani eliningi lomsindo isigaba sokufaka.Lezo zinkinga ezimbili ezishiwo ngenhla zingenzeka uma umamukeli, esigabeni sokufaka, eqhutshwa endaweni yokungahlanganisi umthombo wokuphazamiseka.Ukuze ugweme lezi zinkinga, isiphetho sangaphambili somamukeli kufanele sibe nomugqa oqondile.
Ngakho-ke, "umugqa" nakho kuwukucatshangelwa okubalulekile lapho uklama i-PCB yomamukeli.Njengoba umamukeli kuyisekhethi yebhande elincane, ngakho-ke ukungahambisani nomugqa ukukala “ukuhlanekezela kwe-intermodulation (i-intermodulation distortion)” kuzibalo.Lokhu kuhilela ukusebenzisa amagagasi amabili e-sine noma e-cosine wefrikhwensi efanayo futhi atholakala ebhendini emaphakathi (kwibhendi) ukuze ushayele isignali yokufaka, bese ukala umkhiqizo wokuhlanekezelwa kwawo kwe-intermodulation.Ngokuvamile, i-SPICE iyisofthiwe yokulingisa edla isikhathi futhi ebizayo ngoba kufanele yenze imijikelezo eminingi ngaphambi kokuthi ithole ukulungiswa kwefrikhwensi efunekayo ukuze iqonde ukuhlanekezela.
Ukulingiswa kwesekethe ye-RF yesiginali encane oyifunayo
Umamukeli kufanele azwele kakhulu ukuze abone amasignali amancane okokufaka.Ngokuvamile, amandla okufaka omamukeli angaba mancane njengo-1 μV.ukuzwela kowamukelayo kunqunyelwe umsindo owenziwe yisekethe yokufaka yayo.Ngakho-ke, umsindo uwukucatshangelwa okubalulekile lapho uklama isamukeli se-PCB.Ngaphezu kwalokho, ukuba nekhono lokubikezela umsindo ngamathuluzi okulingisa kubalulekile.Umfanekiso we-1 uyisamukeli esijwayelekile se-superheterodyne (superheterodyne).Isiginali eyamukelwe iyahlungwa kuqala bese isignali yokufaka ikhuliswa nge-low-noise amplifier (LNA).I-oscillator yendawo yokuqala (LO) bese isetshenziselwa ukuxubana nalesi siginali ukuguqula lesi siginali ibe imvamisa ephakathi (IF).Ukuphumelela komsindo wesekethe ekupheleni (ngaphambili-ekugcineni) kuncike kakhulu ku-LNA, i-mixer (i-mixer) ne-LO.nakuba ukusetshenziswa kokuhlaziywa komsindo we-SPICE okuvamile, ungabheka umsindo we-LNA, kodwa ku-mixer ne-LO, akusizi ngalutho, ngoba umsindo kulawa mabhulokhi, uzoba isignali ye-LO enkulu kakhulu ethinteke kakhulu.
Isignali encane yokufaka idinga ukuthi umamukeli akhuliswe ngokwedlulele, ngokuvamile edinga inzuzo efinyelela ku-120 dB.Enzuzweni ephezulu kangako, noma iyiphi isignali ehlanganiswe kusuka kokuphumayo (amabhangqwana) emuva kokokufakayo ingadala izinkinga.Isizathu esibalulekile sokusebenzisa i-super outlier receiver architecture ukuthi ivumela inzuzo ukuthi isatshalaliswe kumafrikhwensi ambalwa ukuze kuncishiswe ithuba lokuhlangana.Lokhu futhi kwenza imvamisa ye-LO yokuqala ihluke kumvamisa yesignali yokufaka, ingavimbela isignali enkulu yokuphazamiseka "ukungcola" kusignali encane yokufaka.
Ngezizathu ezihlukene, kwezinye izinhlelo zokuxhumana ezingenantambo, ukuguqulwa okuqondile (ukuguqulwa okuqondile) noma ukwahluka kwangaphakathi (i-homodyne) izakhiwo zingangena esikhundleni se-ultra-outer differential architecture.Kulesi sakhiwo, isignali yokufaka ye-RF iguqulelwa ngokuqondile kufrikhwensi eyisisekelo ngesinyathelo esisodwa, ukuze inzuzo eningi ibe kumafrikhwensi ayisisekelo futhi i-LO ibe kumafrikhwensi afanayo nesiginali yokufaka.Kulesi simo, umthelela wenani elincane lokuhlanganisa kufanele uqondwe futhi imodeli enemininingwane "yendlela yesignali elahlekile" kufanele isungulwe, njengokuthi: ukuhlanganisa nge-substrate, ukuhlanganisa phakathi kwe-footprint yephakheji kanye nomugqa we-solder (bondwire) , kanye nokuhlanganisa intambo kagesi.
I-RF Circuit Simulation of Adjacent Channel Interference
Ukuhlanekezela nakho kudlala indima ebalulekile kusidlulisi.Ukungatholakali kwe-linearity okukhiqizwe isidluliseli kusekethe yokuphumayo kungase kubangele ububanzi bemvamisa yesiginali edlulisiwe ukuthi sisabalale kumashaneli aseduze.Lesi simo sibizwa ngokuthi "ukukhula kabusha kwe-spectral".Ngaphambi kokuba isignali ifinyelele ku-amplifier yamandla we-transmitter (PA), umkhawulokudonsa wayo unomkhawulo;kodwa-ke, "ukuhlanekezela kwe-intermodulation" ku-PA kubangela umkhawulokudonsa futhi.Uma umkhawulokudonsa ukhula kakhulu, umthumeli ngeke akwazi ukuhlangabezana nezidingo zamandla zamashaneli angomakhelwane.Lapho uthumela isignali yokushintshashintsha yedijithali, cishe akunakwenzeka ukubikezela ukukhula kabusha kwe-spectrum nge-SPICE.Ngoba cishe izimpawu zedijithali eziyi-1000 (uphawu) lomsebenzi wokudlulisela kumele zilingiswe ukuze kutholwe i-spectrum emele, futhi futhi kudingeka kuhlanganiswe umthwali wamafrikhwensi aphezulu, lokhu kuzokwenza ukuhlaziywa kwesikhashana kwe-SPICE kungenzeki.
Isikhathi sokuthumela: Mar-31-2022