I-Anti-interference iyisixhumanisi esibaluleke kakhulu ekwakhiweni kwesifunda sesimanje, okubonisa ngokuqondile ukusebenza nokuthembeka kwalo lonke uhlelo. Konjiniyela be-PCB, i-anti-interference design iyinhloko nephuzu elinzima okufanele wonke umuntu alazi kahle.
Ukuba khona kokuphazamiseka ebhodini le-PCB
Ocwaningweni lwangempela, kutholakala ukuthi kukhona iziphazamiso ezine eziyinhloko ekwakhiweni kwe-PCB: umsindo wokuphakelwa kwamandla kagesi, ukuphazamiseka kolayini wokudlulisa, ukuhlangana kanye nokuphazanyiswa kuka-electromagnetic (EMI).
1. Umsindo wokuphakelwa kwamandla
Emjikelezweni we-high-frequency, umsindo wokunikezwa kwamandla unethonya elicacile ikakhulukazi kusignali ye-high-frequency. Ngakho-ke, imfuneko yokuqala yokunikezwa kwamandla ngumsindo ophansi. Lapha, indawo ehlanzekile ibaluleke njengomthombo wamandla ohlanzekile.
2. Ulayini wokudlulisela
Kunezinhlobo ezimbili kuphela zemigqa yokudlulisela engenzeka ku-PCB: ulayini we-strip nolayini we-microwave. Inkinga enkulu ngelayini yokudlulisela ukubonakaliswa. Ukucabanga kuzodala izinkinga eziningi. Isibonelo, isignali yomthwalo izoba yi-superposition yesiginali yokuqala kanye nesignali ye-echo, okuzokwandisa ubunzima bokuhlaziywa kwesignali; ukucabangela kuzobangela ukulahlekelwa kokubuyisela (ukubuyisela ukulahlekelwa), okuzothinta isignali. Umthelela ubucayi njengalowo obangelwa ukuphazamiseka komsindo okungeziwe.
3. Ukuhlanganisa
Isignali yokuphazamisa ekhiqizwe umthombo wokuphazamiseka idala ukuphazamiseka kazibuthe kagesi ohlelweni lokulawula lwe-elekthronikhi ngesiteshi esithile sokuhlanganisa. Indlela yokuhlanganisa yokuphazamisa ayiyona into edlula ukusebenza ohlelweni lokulawula i-elekthronikhi ngezintambo, izikhala, imigqa evamile, njll. Ukuhlaziywa ikakhulukazi kuhlanganisa lezi zinhlobo ezilandelayo: ukuhlanganisa okuqondile, ukuhlanganisa okujwayelekile kwe-impedance, i-capacitive coupling, i-electromagnetic induction coupling, i-radiation coupling, njll.
4. Ukuphazanyiswa kwe-electromagnetic (EMI)
I-Electromagnetic interference EMI inezinhlobo ezimbili: ukuphazamiseka okwenziwe kanye nokuphazamiseka kwemisebe. Ukuphazamiseka okwenziwayo kubhekisela ekuhlanganisweni (ukuphazamiseka) kwamasignali kunethiwekhi eyodwa kagesi kwenye inethiwekhi kagesi ngokusebenzisa i-conductive medium. Ukuphazamiseka okunemisebe kubhekisela ekuhlanganiseni komthombo wokuphazamiseka (ukuphazamiseka) isignali yayo kwenye inethiwekhi kagesi ngesikhala. Kumklamo we-PCB enesivinini esikhulu kanye nesistimu, imigqa yesiginali yemvamisa ephezulu, izikhonkwane zesekethe ezididiyelwe, izixhumi ezihlukahlukene, njll. zingase zibe imithombo yokuphazamiseka kwemisebe enezici ze-antenna, ezingakhipha amagagasi kagesi futhi zithinte ezinye izinhlelo noma ezinye izinhlelo ezingaphansi ohlelweni. umsebenzi ojwayelekile.
I-PCB nezinyathelo zokulwa nokuphazamiseka kwesekethe
I-anti-jamming design yebhodi lesifunda ephrintiwe ihlobene eduze nesifunda esithile. Okulandelayo, sizokwenza kuphela izincazelo ezithile ezinyathelweni ezimbalwa ezijwayelekile ze-PCB anti-jamming design.
1. Umklamo wentambo yamandla
Ngokusho kobukhulu bebhodi lesifunda eliphrintiwe lamanje, zama ukwandisa ububanzi bomugqa wamandla ukuze unciphise ukumelana kwe-loop. Ngesikhathi esifanayo, yenza isiqondiso solayini wamandla kanye nentambo yaphansi ihambisane nesiqondiso sokudluliswa kwedatha, okusiza ukuthuthukisa ikhono lokulwa nomsindo.
2. Umklamo wocingo ophansi
Hlukanisa umhlabathi wedijithali endaweni ye-analog. Uma kukhona kokubili ama-logic circuits nama-linear circuits ebhodini lesifunda, kufanele ahlukaniswe ngangokunokwenzeka. Umhlabathi wesifunda se-low-frequency kufanele usekelwe ngokuhambisana endaweni eyodwa ngangokunokwenzeka. Uma izintambo zangempela zinzima, zingaxhunywa kancane ochungechungeni bese zisekelwe ngokuhambisana. Isekhethi ye-high-frequency kufanele isekelwe ezindaweni eziningi ochungechungeni, ucingo oluphansi kufanele lube lufushane futhi lube ugqinsi, futhi i-foil yaphansi efana negridi kufanele isetshenziswe eduze kwengxenye yefrikhwensi ephezulu.
Ucingo oluphansi kufanele lube lukhulu ngangokunokwenzeka. Uma umugqa omncane kakhulu usetshenziselwa ucingo oluphansi, amandla okumisa phansi ashintsha ne-current, okunciphisa ukumelana nomsindo. Ngakho-ke, ucingo oluphansi kufanele luqiniswe ukuze ludlule izikhathi ezintathu zamanje ezivumelekile ebhodini eliphrintiwe. Uma kungenzeka, ucingo oluphansi kufanele lube ngaphezu kuka-2~3mm.
Intambo yaphansi yenza iluphu evaliwe. Kumabhodi aphrintiwe akhiwe ngamasekhethi edijithali kuphela, iningi lamasekethe awo aphansi ahlelwa ngamalophu ukuze kuthuthukiswe ukumelana nomsindo.
3. I-Decoupling capacitor ukucushwa
Enye yezindlela ezijwayelekile zokuklama kwe-PCB ukulungisa ama-capacitor afanelekile okuxhuma engxenyeni ngayinye ebalulekile yebhodi eliphrintiwe.
Izimiso zokucushwa ezijwayelekile ze-decoupling capacitor yilezi:
① Xhuma i-electrolytic capacitor engu-10 ~ 100uf kukho konke okokufaka kwamandla. Uma kungenzeka, kungcono ukuxhuma ku-100uF noma ngaphezulu.
②Eqinisweni, i-chip ngayinye yesekethe edidiyelwe kufanele ifakwe i-ceramic capacitor engu-0.01pF. Uma igebe lebhodi eliphrintiwe linganele, i-1-10pF capacitor ingahlelwa kuwo wonke ama-chips angu-4~8.
③Kumadivayisi anamandla okulwa nomsindo abuthaka kanye nezinguquko ezinkulu zamandla lapho ecishiwe, njengamadivayisi esitoreji se-RAM ne-ROM, i-decoupling capacitor kufanele ixhunywe ngokuqondile phakathi kwelayini yamandla kanye nolayini ophansi we-chip.
④I-capacitor lead akufanele ibe yinde kakhulu, ikakhulukazi i-high frequency bypass capacitor akufanele ibe nomthofu.
4. Izindlela zokuqeda ukuphazamiseka kwe-electromagnetic ekwakhiweni kwe-PCB
①Nciphisa amaluphu: Iluphu ngayinye ilingana ne-antenna, ngakho-ke sidinga ukunciphisa inani lamaluphu, indawo yeluphu kanye nomthelela we-antenna weluphu. Qinisekisa ukuthi isignali inomzila weluphu eyodwa kunoma yimaphi amaphoyinti amabili, gwema izihibe zokwenziwa, bese uzama ukusebenzisa isendlalelo samandla.
②Ukuhlunga: Ukuhlunga kungasetshenziswa ukunciphisa i-EMI kokubili entanjeni yamandla nakulayini wesiginali. Kunezindlela ezintathu: ama-decoupling capacitor, izihlungi ze-EMI, nezingxenye kazibuthe.
③Isihlangu.
④ Zama ukwehlisa isivinini samadivayisi anemvamisa ephezulu.
⑤ Ukwandisa i-dielectric constant yebhodi le-PCB kungavimbela izingxenye zefrikhwensi ephezulu njengolayini wokudlulisela oseduze nebhodi ukuthi ungaphumeleli ngaphandle; ukwandisa ukushuba kwebhodi le-PCB nokunciphisa ukujiya komugqa we-microstrip kungavimbela intambo kagesi ukuthi ingachichima futhi kuvimbele nemisebe.