I-RFI isho amandla kazibuthe kagesi angafuneki ebangeni lefrikhwensi lapho ekhiqizwa ukuxhumana nomsakazo.Ububanzi bemvamisa yento yokuqhuba busukela ku-10kHz kuye ku-30MHz;ububanzi befrikhwensi yesenzo semisebe siphakathi kuka-30MHz no-1GHz.
Kunezizathu ezimbili zokuthi kungani i-RFI kufanele icatshangelwe: (1) Imikhiqizo yabo kufanele isebenze ngokujwayelekile ezindaweni abasebenza kuzo, kodwa indawo yokusebenza ngokuvamile ihambisana ne-RFI enzima.(2) Imikhiqizo yabo ayikwazi ukukhanyisa i-RFI ukuze iqinisekise ukuthi ayiphazamisi ukuxhumana kwe-RF okubalulekile kokubili kwezempilo nokuphepha.Umthetho wenze ilungiselelo lokuxhumana okuthembekile kwe-RF ukuze kuqinisekiswe ukulawulwa kwe-RFI kwezinto zikagesi.
I-RFI idluliselwa ngemisebe (amaza kagesi endaweni yamahhala) futhi idluliswa ngomugqa wesiginali kanye nohlelo lwamandla e-AC.
Imisebe - omunye wemithombo ebaluleke kakhulu yemisebe ye-RFI evela kumishini kagesi ulayini wamandla we-AC.Ngenxa yokuthi ubude bolayini wamandla we-AC bufinyelela ku-1/4 we-wavelength ehambisanayo yemishini yedijithali kanye nogesi oshintshwayo, lokhu kwenza uthi olusebenzayo.
Ukuqhuba—I-RFI iqhutshwa ngezindlela ezimbili ohlelweni lokuphakela amandla e-AC.Ifilimu evamile (i-asymmetric) i-RFI ivela ezindleleni ezimbili: emhlabathini womugqa (LG) kanye nomhlabathi ongathathi hlangothi (NG), kuyilapho imodi yokuhlukanisa (i-symmetric) i-RFI ivela kulayini wokungathathi hlangothi (LN) ngesimo se-voltage.
Ngokuthuthuka okusheshayo kwezwe namuhla, amandla kagesi amaningi futhi aphezulu akhiqizwa.Ngesikhathi esifanayo, amandla kagesi amaningi futhi aphansi asetshenziselwa ukudlulisa nokucubungula idatha, ukuze akhiqize ithonya elikhulu futhi ngisho nokuphazamiseka komsindo kucekela phansi imishini kagesi.Isihlungi sokugxambukela kwelayini kagesi ingenye yezindlela zokuhlunga eziyinhloko ezisetshenziswa ukulawula i-RFI kusukela ocingweni lwe-elekthronikhi ukuze ingene (ukungasebenzi kahle kwemishini okungenzeka) futhi iphume (ukuphazamiseka okungenzeka kwezinye izinhlelo noma ukuxhumana kwe-RF).Ngokulawula i-RFI kupulaki yamandla, isihlungi solayini wamandla siphinde sinqande kakhulu imisebe ye-RFI.
Isihlungi solayini wamandla siyingxenye yenethiwekhi yamashaneli amaningi, ehlelwa ngesakhiwo sokuhlunga amashaneli aphansi kabili.Inethiwekhi eyodwa isetshenziselwa ukuncishiswa kwemodi evamile, kanti enye ingeyokuthobisa imodi yokuhlukanisa.Inethiwekhi ihlinzeka ngokuncishiswa kwamandla e-RF "kubhendi yokumisa" (imvamisa engaphezu kuka-10kHz) yesihlungi, kuyilapho esamanje (50-60Hz) empeleni singanciphisiwe.
Njengenethiwekhi ye-passive ne-bilateral, isihlungi sokuphazamiseka komugqa wamandla sinesici sokushintsha esiyinkimbinkimbi, esincike kakhulu emthonjeni nasekuvimbelweni komthwalo.Isici sokunciphisa isihlungi siboniswa yivelu yesici sokuguqulwa.Kodwa-ke, endaweni yolayini wamandla, umthombo nokuphazamiseka komthwalo akuqinisekile.Ngakho-ke, kunendlela evamile yokuqinisekisa ukuvumelana kwesihlungi embonini: ukulinganisa ileveli yokunciphisa ngomthombo ophikisayo ongu-50 ohm kanye nesiphetho somthwalo.Inani elilinganisiwe lichazwa njengokulahlekelwa kokufakwa (IL) kwesihlungi:
I..L.= 10 log * (P(l)(Ref)/P(l))
Lapha i-P (L) (Ref) ingamandla aguqulwa ukusuka emthonjeni ukuya emthwalweni (ngaphandle kwesihlungi);
I-P (L) amandla okuguqula ngemva kokufaka isihlungi phakathi komthombo nomthwalo.
Ukulahlekelwa kokufaka kungase futhi kuvezwe ngesilinganiso se-voltage esilandelayo noma samanje:
IL = 20 log *(V(l)(Ref)/V(l)) IL = 20 log *(I(l)(Ref)/I(l))
Lapha u-V (L) (Ref) kanye no-I (L) (Ref) amanani alinganiselwe ngaphandle kwesihlungi,
U-V (L) kanye no-I (L) amanani akalwa ngesihlungi.
Ukulahlekelwa kokufaka, okufanele kuqashelwe, akumeli ukusebenza kokunciphisa kwe-RFI okuhlinzekwa yisihlungi endaweni yelayini yamandla.Esimeni sezintambo zamandla, inani elihlobene lomthombo kanye nokuthikamezeka komthwalo kufanele kulinganiswe, futhi isakhiwo sokuhlunga esifanelekile sikhethwa ukuze senze umkhawulo omkhulu ongase ube khona wokuphazamiseka kokushayisana kutheminali ngayinye.Isihlungi sincike ekusebenzeni kwe-terminal impedance, okuyisisekelo somqondo "wenethiwekhi yokungafani".
Ukuhlolwa kokusebenza kudinga indawo ethule ye-RF - igobolondo lesivikelo - inethiwekhi yokuqinisa umugqa, kanye nethuluzi le-voltage ye-RF (njengesamukeli se-FM noma isihlazisi spectrum).Imvelo ye-RF yokuhlolwa kufanele okungenani ibe ngaphansi komkhawulo odingekayo ongu-20dB ukuze kutholwe imiphumela yokuhlolwa enembile.Inethiwekhi ye-linear impedance stabilization (LISN) iyadingeka ukuze kusungulwe i-impedance yomthombo oyifunayo yokufakwayo kwentambo yamandla, okuyingxenye ebaluleke kakhulu yohlelo lokuhlola ngoba i-impedance ithinta ngokuqondile izinga lemisebe elilinganisiwe.Ngaphezu kwalokho, isilinganiso esifanele se-broadband somamukeli futhi siyipharamitha eyinhloko yokuhlolwa.
Isikhathi sokuthumela: Mar-30-2021
