M'kati mwa mapangidwe a PCB, tisanayende, timayika zinthu zomwe tikufuna kupanga, ndikuwerengera zolepheretsa kutengera makulidwe, gawo lapansi, kuchuluka kwa zigawo ndi zina. Pambuyo powerengera, zotsatirazi zitha kupezeka.

Monga tikuwonera pachithunzichi, mawonekedwe amtundu wamtundu umodzi pamwambapa nthawi zambiri amayendetsedwa ndi 50 ohms, kotero anthu ambiri amafunsa chifukwa chake ndikofunikira kuwongolera molingana ndi 50 ohms m'malo mwa 25 ohms kapena 80 ohms?
Choyamba, 50 ohms amasankhidwa mwachisawawa, ndipo aliyense mumakampani amavomereza mtengowu. Nthawi zambiri, muyezo wina uyenera kupangidwa ndi bungwe lodziwika bwino, ndipo aliyense akupanga mogwirizana ndi muyezowo.
Mbali yaikulu ya teknoloji yamagetsi imachokera ku usilikali. Choyamba, lusoli limagwiritsidwa ntchito m'magulu ankhondo, ndipo limasamutsidwa pang'onopang'ono kuchoka ku usilikali kupita kwa anthu wamba. M'masiku oyambirira a ntchito za microwave, pa Nkhondo Yachiwiri Yadziko Lonse, kusankha kwa impedance kunali kodalira pa zosowa za ntchito, ndipo panalibe mtengo wokhazikika. Ndi kupita patsogolo kwaukadaulo, miyezo ya impedance ikuyenera kuperekedwa kuti pakhale mgwirizano pakati pa chuma ndi kumasuka.

Ku United States, njira zomwe zimagwiritsidwa ntchito kwambiri zimalumikizidwa ndi ndodo zomwe zilipo kale komanso mapaipi amadzi. 51.5 ohms ndizofala kwambiri, koma ma adapter ndi otembenuza omwe amawonedwa ndikugwiritsidwa ntchito ndi 50-51.5 ohms; izi zathetsedwa kwa gulu limodzi lankhondo ndi apamadzi. Vuto, bungwe lotchedwa JAN lidakhazikitsidwa (kenako bungwe la DESC), lopangidwa mwapadera ndi MIL, ndipo pomaliza linasankha ma ohm 50 ataganizira mozama, ndipo ma catheter ogwirizana adapangidwa ndikusinthidwa kukhala zingwe zosiyanasiyana. Miyezo.

Panthawiyi, muyezo waku Europe unali 60 ohms. Posakhalitsa, motsogozedwa ndi makampani akuluakulu monga Hewlett-Packard, Azungu nawonso adakakamizika kusintha, kotero 50 ohms pamapeto pake idakhala muyezo mumakampani. Yakhala msonkhano, ndipo PCB yolumikizidwa ndi zingwe zosiyanasiyana imafunikira kuti igwirizane ndi 50 ohm impedance standard yofananira ndi impedance.

Kachiwiri, kupangidwa kwa miyezo wamba kudzakhazikitsidwa pamalingaliro athunthu akupanga kwa PCB ndi kapangidwe kake ndi kuthekera.

Kuchokera ku kaonedwe ka PCB kupanga ndi luso processing, ndi kuganizira zida za opanga ambiri alipo PCB, n'zosavuta kupanga PCBs ndi 50 ohm impedance. Kuchokera pa kuwerengera kwa impedance, zikhoza kuwoneka kuti kulepheretsa kutsika kwambiri kumafuna mzere wochuluka wa mzere ndi sing'anga yopyapyala kapena yowonjezereka ya dielectric nthawi zonse, zomwe zimakhala zovuta kwambiri kukumana ndi bolodi lamakono lapamwamba kwambiri mumlengalenga; kulepheretsa kwambiri kumafuna mzere wocheperako Makanema otambalala ndi okhuthala kapena ma dielectric okhazikika samathandizira kupondereza EMI ndi crosstalk. Panthawi imodzimodziyo, kudalirika kwa kukonza kwa matabwa amitundu yambiri komanso kuchokera pakupanga kwakukulu kudzakhala kosauka. Yang'anirani 50 ohm impedance. Pansi chilengedwe ntchito matabwa wamba (FR4, etc.) ndi wamba pachimake matabwa, kupanga wamba bolodi makulidwe mankhwala (monga 1mm, 1.2mm, etc.). Wamba mizere m'lifupi (4 ~ 10mil) akhoza kupangidwa. Fakitale ndiyosavuta kukonza, ndipo zofunikira za zida zogwirira ntchito zake sizokwera kwambiri.

Kuchokera pamawonekedwe a PCB, 50 ohms imasankhidwanso pambuyo poganizira mozama. Kuchokera pamachitidwe amtundu wa PCB, kusokoneza pang'ono kumakhala bwinoko. Kwa mzere wopatsira wokhala ndi mzere wopatsidwa m'lifupi, pafupi ndi mtunda wa ndegeyo, EMI yofananira idzachepetsedwa, ndipo crosstalk idzachepetsedwanso. Komabe, poyang'ana njira yonse yazizindikiro, chimodzi mwazinthu zofunika kwambiri ziyenera kuganiziridwa, ndiko kuti, kuyendetsa bwino kwa chip. M'masiku oyambilira, tchipisi zambiri sizikanatha kuyendetsa mizere yopatsirana yokhala ndi zopinga zosakwana 50 ohms, ndipo mizere yopatsira yokhala ndi zopinga zambiri zinali zovuta kuziyika. Chifukwa chake 50 ohm impedance imagwiritsidwa ntchito ngati kunyengerera.

Gwero: Nkhaniyi yasamutsidwa kuchokera pa intaneti, ndipo ufuluwo ndi wa wolemba woyambirira.