Pakali pano, high-frequency ndi liwiro PCB kapangidwe kakhala kofala, ndipo injiniya aliyense wa PCB Layout ayenera kukhala waluso. Chotsatira, Banermei akugawana nanu zina mwazojambula za akatswiri a hardware m’mabwalo othamanga kwambiri komanso othamanga kwambiri a PCB, ndipo ndikukhulupirira kuti zidzakhala zothandiza kwa aliyense.

1. Kodi mungapewe bwanji kusokoneza kwafupipafupi?

Lingaliro lofunikira popewa kusokonezedwa ndi ma frequency apamwamba ndikuchepetsa kusokoneza kwa ma elekitiroma a ma frequency apamwamba, omwe amatchedwa crosstalk (Crosstalk). Mukhoza kuonjezera mtunda pakati pa chizindikiro chothamanga kwambiri ndi chizindikiro cha analogi, kapena kuwonjezera mawonedwe apansi / shunt pafupi ndi chizindikiro cha analogi. Komanso tcherani khutu ku kusokoneza kwa phokoso kuchokera kumalo a digito kupita kumalo a analogi.

2. Kodi mungaganizire bwanji zofananira popanga mapangidwe apamwamba kwambiri a PCB?

Mukapanga mabwalo othamanga kwambiri a PCB, kufananitsa kwa impedance ndi chimodzi mwazinthu zomwe zimapangidwira. Mtengo wa impedance uli ndi ubale wokhazikika ndi njira yolumikizira, monga kuyenda pamtunda (microstrip) kapena wosanjikiza wamkati (stripline/double stripline), mtunda kuchokera pagawo lolozera (mphamvu wosanjikiza kapena wosanjikiza pansi), m’lifupi mwa waya, zinthu za PCB. , ndi zina zotere. Zonse zidzakhudza mtengo wolepheretsa kutsata. Ndiko kunena kuti, mtengo wa impedance ukhoza kutsimikiziridwa pambuyo pa waya. Nthawi zambiri, mapulogalamu oyerekeza sangaganizire zina zama waya zomwe zimakhala ndi vuto losiya chifukwa cha kuchepa kwa mtundu wadera kapena masamu omwe amagwiritsidwa ntchito. Panthawi imeneyi, otsiriza ena (kuthetsa), monga kukana mndandanda, akhoza kusungidwa pa chithunzi cha schematic. Chepetsani zotsatira za discontinuity mu trace impedance. Yankho lenileni la vutoli ndi kuyesa kupewa impedance discontinuities pamene mawaya.

3. Pamapangidwe othamanga kwambiri a PCB, ndi mbali ziti zomwe wopanga ayenera kuganizira za malamulo a EMC ndi EMI?

Nthawi zambiri, mapangidwe a EMI/EMC amayenera kuganizira zowunikira komanso kuchitidwa nthawi imodzi. Yoyamba ndi ya gawo lapamwamba la pafupipafupi (<30MHz) ndipo yomalizayo ndi gawo lapafupipafupi (<30MHz). Kotero inu simungakhoze basi kulabadira mkulu pafupipafupi ndi kunyalanyaza otsika pafupipafupi gawo. Mapangidwe abwino a EMI / EMC ayenera kuganizira malo a chipangizocho, makonzedwe a stack PCB, njira yolumikizira yofunika, kusankha kwa chipangizo, ndi zina zotero kumayambiriro kwa masanjidwewo. Ngati palibe makonzedwe abwinoko pasadakhale, adzathetsedwa pambuyo pake. Idzachita kawiri zotsatira zake ndi theka la khama ndikuwonjezera mtengo. Mwachitsanzo, malo a jenereta ya wotchi sayenera kukhala pafupi ndi cholumikizira chakunja. Zizindikiro zothamanga kwambiri ziyenera kupita kumalo amkati momwe zingathere. Samalani ndi mawonekedwe a impedance ndi kupitiliza kwa gawo lolozera kuti muchepetse zowunikira. Mlingo wakupha wa chizindikiro chokankhidwa ndi chipangizocho uyenera kukhala wocheperako kuti uchepetse kutalika. Zigawo zafupipafupi, posankha decoupling / bypass capacitor, samalani ngati kuyankha kwake pafupipafupi kumakwaniritsa zofunikira kuti muchepetse phokoso pa ndege yamagetsi. Kuonjezera apo, tcherani khutu ku njira yobwereranso yamagetsi apamwamba kwambiri kuti apange malo ozungulira kukhala ang’onoang’ono momwe angathere (ndiko kuti, loop impedance yaying’ono momwe mungathere) kuchepetsa ma radiation. Pansi amathanso kugawidwa kuti aziwongolera kuchuluka kwa phokoso lambiri. Pomaliza, sankhani bwino malo a chassis pakati pa PCB ndi nyumba.

4. Kodi kusankha PCB bolodi?

Kusankhidwa kwa bolodi la PCB kuyenera kukhala koyenera pakati pa zomwe zimafunikira pakukonza ndi kupanga misa ndi mtengo. Zofunikira pakupanga zimaphatikizapo mbali zonse zamagetsi ndi zamakina. Nthawi zambiri vuto la zinthuli ndi lofunika kwambiri popanga matabwa a PCB othamanga kwambiri (ma frequency akulu kuposa GHz). Mwachitsanzo, zinthu zomwe zimagwiritsidwa ntchito nthawi zambiri za FR-4, kutayika kwa dielectric pafupipafupi kwa ma GHz angapo kudzakhala ndi chikoka chachikulu pakuchepetsa ma siginecha, ndipo mwina sikungakhale koyenera. Ponena za magetsi, samalani ngati kutayika kwa dielectric ndi dielectric ndi koyenera kwa ma frequency opangidwa.

5. Momwe mungakwaniritsire zofunikira za EMC momwe mungathere popanda kupangitsa kuti pakhale zovuta zambiri?

Kuwonjezeka kwa mtengo wa bolodi la PCB chifukwa cha EMC nthawi zambiri kumakhala chifukwa cha kuchuluka kwa zigawo zapansi kuti zithandizire chitetezo komanso kuwonjezera kwa ferrite bead, kutsamwitsa ndi zida zina zapamwamba zopondereza za harmonic. Kuphatikiza apo, nthawi zambiri pamafunika kufananiza mawonekedwe oteteza mabungwe ena kuti dongosolo lonse likwaniritse zofunikira za EMC. Zotsatirazi zimangopereka njira zingapo zopangira ma board a PCB kuti muchepetse mphamvu yamagetsi yamagetsi yopangidwa ndi dera.

Yesani kusankha chipangizo chokhala ndi siginecha yocheperako kuti muchepetse ma frequency apamwamba opangidwa ndi siginecha.

Samalani kuyika kwa zigawo zapamwamba kwambiri, osati pafupi kwambiri ndi cholumikizira chakunja.

Samalani kufananiza kwa ma impedans othamanga kwambiri, wosanjikiza wama waya ndi njira yake yobwereranso, kuti muchepetse chiwonetsero chambiri komanso ma radiation.

Ikani ma capacitors okwanira komanso oyenerera pazikhomo zamagetsi a chipangizo chilichonse kuti muchepetse phokoso pa ndege yamagetsi ndi ndege yapansi. Samalani kwambiri ngati kuyankha pafupipafupi ndi kutentha kwa capacitor kumakwaniritsa zofunikira za mapangidwe.

Pansi pafupi ndi cholumikizira chakunja chikhoza kupatulidwa bwino kuchokera pansi, ndipo pansi pa cholumikizira chikhoza kulumikizidwa ku chassis pansi pafupi.

Malonda apansi / shunt angagwiritsidwe ntchito moyenera pambali pa zizindikiro zina zapadera zothamanga kwambiri. Koma tcherani khutu ku kukopa kwa alonda / shunt pamakhalidwe omwe amatsata.

Mphamvu yamagetsi imachepa 20H kuchokera pansi, ndipo H ndi mtunda pakati pa mphamvu ya mphamvu ndi nthaka.

6. Ndi mbali ziti zomwe ziyenera kutsatiridwa popanga, mayendedwe ndi masanjidwe a ma frequency apamwamba a PCB pamwamba pa 2G?

Ma PCB othamanga kwambiri pamwamba pa 2G ndi a kapangidwe ka ma frequency a wailesi ndipo sali mkati mwa zokambirana zamapangidwe apamwamba kwambiri a digito. Masanjidwe ndi kachitidwe ka ma frequency a wayilesi ayenera kuganiziridwa pamodzi ndi schematiki, chifukwa masanjidwe ndi njira zingayambitse kugawa. Kuphatikiza apo, zida zina zokhazikika pamapangidwe a ma frequency ma radio frequency zimazindikirika kudzera mu matanthauzo a parameterized ndi zojambula zamkuwa zooneka mwapadera. Chifukwa chake, zida za EDA zimafunikira kupereka zida zofananira ndikusintha zojambula zamkuwa zooneka mwapadera. Mentor’s boardstation ili ndi gawo lapadera la kapangidwe ka RF lomwe lingakwaniritse izi. Kuphatikiza apo, mapangidwe a RF wamba amafunikira zida zapadera zowunikira ma RF. Odziwika kwambiri pamakampani ndi eesoft agilent, omwe ali ndi mawonekedwe abwino ndi zida za Mentor.

7. Kodi kuwonjezera mfundo zoyesa kungakhudze khalidwe la zizindikiro zothamanga kwambiri?

Kaya zidzakhudza khalidwe la chizindikiro zimadalira njira yowonjezerapo mfundo zoyesera komanso momwe chizindikirocho chimakhalira mofulumira. Kwenikweni, mfundo zowonjezera zoyesera (musagwiritse ntchito zomwe zilipo kudzera kapena pini ya DIP ngati mfundo zoyesa) zikhoza kuwonjezeredwa pamzere kapena kukoka mzere waufupi kuchokera pamzere. Zakale ndizofanana ndi kuwonjezera capacitor yaying’ono pamzere, yotsirizirayi ndi nthambi yowonjezera. Zonse ziwirizi zidzakhudza chizindikiro chothamanga kwambiri kapena chocheperapo, ndipo momwe zotsatira zake zimayenderana ndi maulendo afupipafupi a chizindikiro ndi m’mphepete mwa chizindikiro. Kukula kwa chikokacho kungadziwike kupyolera mu kuyerekezera. M’malo mwake, malo oyesera ang’onoang’ono, abwino (ndithudi, ayenera kukwaniritsa zofunikira za chida choyesera) ndi yochepa nthambi, bwino.