Idizayini ye-PIM ye-PCB ephansi: Izindlela Zesiginali Ezihlanzekile Zobunjiniyela Ezinhlelweni Zemvamisa Ephakeme

Isingeniso

Njengoba amasistimu angenantambo ephushela kumafrikhwensi aphezulu kanye nezidingo zomugqa oqinile, idizayini ephansi ye-PIM PCB iba semqoka ekugcineni imizila yesiginali ehlanzekile kanye nokunciphisa ukuhlanekezela okungafunwa. I-Passive Intermodulation (PIM) imelela ukuphazamiseka okukhiqizwa lapho amasiginali e-RF ehlangana nezinto ezingaqondile ezingxenyeni ze-passive, okubangela ukukhishwa okungelona iqiniso okwehlisa ukusebenza kwesistimu.

Kungqalasizinda yesimanje ye-5G, ezokuxhumana ngesathelayithi, nezinhlelo zokusebenza ze-radar ezisebenza kumafrikhwensi e-multi-gigahertz, ngisho nokungafinyeleli kweminithi okungeyona i-linearities kukhiqiza ukuphazamiseka okulinganisekayo. Idizayini ephansi ye-PIM PCB ibhekana nale nselele ngokukhethwa kwezinto ezihlelekile, ukwenziwa ngcono kokwelashwa okungaphezulu, nezinqubo zokukhiqiza ezilawulwayo.

Eziteshini eziyisisekelo zamaselula lapho amabhendi okudlulisa nokwamukela asebenza ngesikhathi esisodwa, imikhiqizo ye-intermodulation ye-oda lesithathu ingawela ngokuqondile eziteshini zokwamukela ezizwelayo, kunciphise ukuzwela kwesistimu ngo-10 dB noma ngaphezulu. Idizayini efanele ephansi ye-PIM PCB iqinisekisa ubuqotho besignali buhlala bungenasici kulo lonke uchungechunge lwe-RF.

Ukuqonda i-Passive Intermodulation (PIM)

I-PIM Formation Mechanisms

I-Passive Intermodulation kwenzeka lapho amasiginali e-RF amabili noma ngaphezulu ehlangana ngokuhlangana okungaqondile ezakhiweni ezibizwa ngokuthi i-passive, kwakheka izingxenye ezingamanga zamafrikhwensi ekuhlanganisweni okuphelele kwamafrikhwensi okokufaka. Uma abathwali ku-f₁ naku-f₂ benqamula isixhumi esibonakalayo esingaqondile, bakhiqiza imikhiqizo ku-2f₁–f₂, 2f₂–f₁, nezinhlanganisela ze-oda eliphezulu. Ngokungafani ne-intermodulation esebenzayo kuma-amplifiers, i-PIM ivela kokuthintwa kwensimbi kuya kwensimbi, indawo ene-oxidized, ukungcola kwe-ferromagnetic, nokungalungi kwendawo okubonakalayo okubonisa ukusebenza okuncike kwamanje.

I-Active Versus Passive Intermodulation

I-intermodulation esebenzayo isuka ekuhlanganeni kwe-semiconductor lapho ukucutshungulwa kwesignali ngamabomu kwenzeka, kulandela imisebenzi yokudlulisa ebikezelwe. I-passive intermodulation ibonakala ezakhiweni okuthiwa ziwumugqa ngokuxhumana okungaqondile, imiphumela ye-electrochemical ezindaweni ezingafani zensimbi, kanye nokushisisa okwenziwe okwamanje okushintsha ukusebenza kahle. I-PIM ifakazela ukuthi iyinkinga ikakhulukazi ngoba ibonakala ngokungalindelekile, iyahlukahluka nezimo zemvelo, futhi ingavela ngenxa yokulimala kokukhiqiza okungabonakali ekuhlolweni kukagesi okujwayelekile.

Ukuzwela Imvamisa Kuzakhiwo ze-PCB

Ubukhulu be-PIM buyakhuphuka kumaza we-gigahertz lapho umphumela wesikhumba ugxila khona manje emingceleni yangaphezulu, okwandisa umthelela wokugwedla kwendawo nezingqimba ze-oxide. Ku-2 GHz nangaphezulu, ukuhlukahluka kwendawo engaphansi kwe-submicron iba ngokubaluleka ngogesi, okwenza ikhwalithi yendawo ye-PCB ibe phambili ekusebenzeni okuphansi kwe-PIM PCB. Ukuhamba ngebhayisikili okunezinga lokushisa kubhebhethekisa le miphumela njengoba ukunwetshwa okushisayo okuhlukile kudala ukunyakaza okubonakalayo ezindaweni zokusebenzelana, kushintsha ukumelana nokuxhumana.

Imbangela ye-PIM ku-Low PIM PCB Design

Abanikeli Abahlobene Nentokozo

Ubulukhuni bendawo yethusi buthonya ngokuqondile ukukhiqizwa kwe-PIM ngokuminyana kwamanje eziqongweni ezincanyana nezigodi. Ithusi eligoqiwe elinamaphrofayili amabi libonisa i-PIM ephakeme kunethusi eline-electrodeposited ene-controlled surface topology. Izinto ze-Dielectric eziqukethe ama-monomer asele noma umswakama wethula ukungahambisani kwenqwaba, kuyilapho ama-substrates alahlekile akhiqiza ukushisa okushintsha ukusebenza kwendawo ngaphansi kwe-RF yamandla aphezulu.

Imithombo Ehlobene Nomklamo

Izici ezibalulekile zedizayini ezithinta ukusebenza okuphansi kwe-PIM PCB zifaka:

• Ukusatshalaliswa kwamanje - Izindlela ezingezona ezamukelekayo ziphoqa amandla esignali ezindaweni ezikhawulelwe lapho ukuminyana kwamanje kusondela emikhawulweni yezinto
• Ubuqotho bendiza yaphansi - Izindiza ezingaqhubeki zenza izihibe zamanje ezibuyayo ezigxilisa izinkambu emaphethelweni e-PCB
• Ngezakhiwo - Ikhwalithi yokufakwa kwemigqomo inquma ukusebenza kwe-PIM, ikakhulukazi kuma-stackups wokubala okuphezulu
• Ubuningi besixhumi esibonakalayo - Isiphambano ngasinye esengeziwe sethula izindawo zokuxhumana ezingase zibe khona ezingezona umugqa

Ukukhiqiza kanye Nezici Zomhlangano

Izinsalela ze-Solder flux zakha izivimbelo zokuvikela ezindaweni ezibucayi, eziphoqelela okwamanje ngokusebenzisa izindawo zokuxhumana ezincane ezibonisa ukuziphatha okungaqondile. Ukucindezelwa komshini okuvela ekukhwezweni kwesixhumi kudala ama-gradients akhiqiza ukuthintana kwensimbi kuya kwensimbi okungahambisani. Ukungcoliswa ngesikhathi sokwakha kwethula izinto zangaphandle ezinezakhiwo kazibuthe noma umehluko ongaba khona we-electrochemical okhiqiza i-PIM ngaphansi kwe-RF excitation.

Amathonya Ezemvelo

Ukuhamba ngebhayisikili okushisayo kushayela i-oxidation esibonakalayo futhi kudala ukunwetshwa komehluko phakathi kwezinto ezingafani, kulinganisa ukumelana nokuxhumana ngaphezu kwamazinga okushisa okusebenza. Ukungena komswakamo kukhuthaza ukugqwala kwe-electrochemical ezindaweni zethusi eziveziwe kanye nezindawo zokusebenzelana ezinamapulangwe. Lezi zindlela ezincike esikhathini zisho ukuthi ukusebenza kwe-PIM kuyehla ngesikhathi sokuphila komkhiqizo, okwenza amamajini okuqala edizayini abe abalulekile.

I-PIM PCB Design Techniques ephansi kanye Nemikhuba Engcono Kakhulu

Ukukhethwa Kwezinto Ezibalulekile

Umklamo we-PCB we-PIM ephansi uqala ngokukhethwa kwe-substrate okubeka phambili izinto ezibonisa ukungalingani okuncane kwe-dielectric kanye nezici zokuhlakazeka okuphansi. i-laminate ekhethekile ephansi yokulahlekelwa kanye nama-laminate asekelwe ku-PTFE abonisa ukusebenza okuphezulu kwe-PIM ngokuvumela okuzinzile kanye nokumuncwa okuncane komswakama. Ukukhethwa kwe-foil yethusi kugcizelela amaphrofayili abushelelezi atholakala ngokuma kwe-electrode, kanye nama-foil aphathwe emuva anikeza ukugoba okuphansi kobuso. Ukugwema izinto ze-ferromagnetic kubalulekile, njengoba zethula ukungalingani okune-hysteretic ngisho nasemazingeni aphansi amandla.

I-Optimized Surface Finishes

Ukukhetha kokuqedwa kobuso kuthinta kakhulu ukusebenza okuphansi kwe-PIM PCB:

• I-ENIG (Electroless Nickel Immersion Gold) - I-PIM ephakeme ngenxa yezakhiwo ze-nickel ferromagnetic
• I-EPIG (Electroless Palladium Immersion Gold) - Iqeda izinto ezisetshenziswa kazibuthe ngenkathi ihlinzeka ukumelana ne-oxidation
• Isiliva Sokucwiliswa - I-conductivity enhle kakhulu kodwa idinga ukuphathwa ngokucophelela ukuvimbela ukungcoliswa
• I-OSP (I-Organic Solderability Preservative) - Yehlisa ubunkimbinkimbi besixhumi esibonakalayo kodwa inikeza impilo yeshalofu elinganiselwe

Isitaki Esilawulwayo Nesakhiwo

Ukufakwa kwezingqimba ezilinganayo ngezindiza zomhlaba eziqhubekayo kunciphisa ukushintshashintsha kwendlela yamanje futhi kunciphisa amaphuzu okuhlushwa kwensimu. Ukuhanjiswa kwesignali kugcina ukuvimba okulawulwayo phakathi nokushintsha, kugwema izinguquko zobubanzi obungazelelwe noma izikhala zendiza yokubhekisela ezigxila ekuminyaneni kwamanje. Ngomklamo kugcizelela izakhiwo ezigcwele nezifakwe amapulangwe ezisusa izikhala zomoya lapho ukubola kungenzeka khona. Izakhiwo ze-PCB ze-PIM eziphansi zinciphisa inani lesikhombimsebenzisi ngokunciphisa ama-via angadingekile nokuhlanganisa izindlela ze-RF ezibalulekile ezingqimbeni ezilodwa.

Ukuhlanganiswa Kwesixhumi Esinembile

Ukukhetha isixhumi kugxile kumiklamo eqinile ngokusakazwa kwengcindezi yokuxhumana okulawulwayo. I-DIN 7/16 nezixhumi zohlobo lwe-PIM eziphansi ze-PIM zifaka oxhumana nabo be-beryllium yethusi ene-silver-plated enokusebenzelana okulayishwe entwasahlobo egcina ukusebenza kokusebenzelana okungaguquki kulo lonke izinga lokushisa nokudlidliza. Idizayini yoguquko iqeda ukugoba okubukhali futhi iqinisekisa ukuvela kwenkambu ebushelelezi ukusuka ku-coaxial kuya ku-planar geometries.

Ukulawulwa Kwenqubo Yokukhiqiza

Izinqubo zomhlangano zokukhiqiza okuphansi kwe-PIM PCB zifaka:

• Ukulungiswa kwendawo - Ukuhlanza i-solvent kanye nokwelashwa komoya nge-ionized ngaphambi kokuvalelwa kokugcina
• Ukukhetha kokunamathisela kwe-solder - Ukwakheka okuguquguqukayo okunganalaka okunciphisa izinsalela
• Gcwalisa kabusha iphrofayela - Ukulawulwa kokucindezeleka okushisayo ngenkathi uqinisekisa ukumanzisa okuphelele kwe-solder
• Ukuhlolwa kwangemva komhlangano - Ukuhlolwa okubonakalayo kokuhlangana okubalulekile kwe-RF kanye nokunamathela okukhethekile okukhethiwe

Ukuhlola Nokuqinisekisa Ukusebenza Kwe-PIM Ephansi Ye-PCB

I-PIM Testing Methodology

Ukuhlola kwe-PIM okujwayelekile kusebenzisa izinkampani ezimbili zenethiwekhi zamandla aphezulu ezihlukaniswa umkhawulokudonsa wesiteshi, ngokuvamile ku-2×20W (43 dBm), kuyilapho kukalwa imikhiqizo ye-intermodulation ye-oda lesithathu kumafrikhwensi angu-2f₁–f₂ no-2f₂–f₁. Amasistimu okuhlola adinga ukuhlukaniswa okukhethekile okudlula u-160 dB phakathi kwemizila yokudlulisa nokwamukela ukuze kuhlukanise i-PIM yangempela kuma-artifact okulinganisa. Amamojula e-PIM PCB aphansi ayahlolwa emakamelweni avikelwe kusetshenziswa izihlanganisi ezilinganiselwe kanye nemithwalo ye-PIM ephansi.

Imvamisa kanye nobubanzi bamandla

Ukuhlolwa kwengqalasizinda yeselula ngokuvamile kuvame ukusuka ku-700 MHz kuye ku-6 GHz ngamandla okudlulisa ukusuka ku-20W kuye ku-80W inkampani yenethiwekhi ngayinye, okubonisa izimo zokusebenza eziteshini eziyisisekelo ezinkulu. Izinhlelo zokusebenza zesathelayithi zinweba ukuhlola kuye kumafrikhwensi e-Ku-band kanye ne-Ka-band lapho izikhulisamandla zemikhumbi-mkhathi zikhiqiza amandla abalulekile e-RF. Ubudlelwano phakathi kwamandla okufakwayo nemikhiqizo ye-PIM bulandela umthetho we-oda lesithathu noma lesihlanu, okuvumela ukudluliselwa kusuka ezimeni zokuhlola kuye kuzimo zokusebenza.

Izindlela Zokuqinisekisa Zezinga le-PCB

Ukulungiswa kokuhlolwa okunikelwe kunika amandla ukulinganiswa kwe-PIM PCB ephansi ngesikhathi sokuthuthukiswa, ukuhlonza izindawo ezinezinkinga ngaphambi kokuhlanganiswa kwesistimu. Lezi zinhlelo zisebenzisa izixhumi ezinembayo nezinhlaka zokuqalisa ezilawulwayo ukuze zihlukanise iminikelo ye-PCB ezintweni zokuhlola. Amakamelo ashisayo angaphansi kwamabhodi ekushibilikeni kwezinga lokushisa ngenkathi eqapha ukuhlukahluka kwe-PIM, eveza izindlela ezincike kuzinga lokushisa. Amasu okuhlaziya ama-Microanalysis okuhlanganisa ukuskena i-electron microscopy ehlonza ukungcola noma okudidayo kwesakhiwo ezindaweni ezibucayi.

Ukuqaliswa Kokulawula Ikhwalithi

Ukuhlolwa komkhiqizo kusungula imininingwane ye-PIM efanelekile ezidingweni zohlelo lokusebenza, ngokuvamile kusukela ku--110 dBc kuya ku--160 dBc kuye ngokuzwela kohlelo. Ukulawulwa kwenqubo yezibalo kuqapha ukusebenza kwe-PIM kuzo zonke izindawo zokukhiqiza, kuthola ukukhukhuleka kwenqubo ngaphambi kokuba kwenzeke imiphumela yokukhiqiza. Izinqubo zokuhlola ubuso ziqinisekisa ukuhlanzeka kanye nobuqotho bokuqeda emajoyintini e-solder kanye nezixhumi ezixhunywayo.

Izicelo Ezisebenzayo kanye Nomthelela Wokusebenza

Izizinda Zokusebenza Ezibalulekile

Ingqalasizinda yeselula yesizukulwane sesihlanu incike ekwakhiweni okuphansi kwe-PIM PCB ukuze kusekelwe ama-antenna amakhulu e-MIMO lapho amakhulu eziteshi ze-RF esebenza ngesikhathi esisodwa. Amasistimu okuxhumana ngesathelayithi adinga amazinga e-PIM angezansi -150 dBc ukuze avimbele ukuphazanyiswa izamukeli ezibucayi ze-uplink ezicubungula amasignali eduze komsindo phansi. Izinhlelo zokusebenza ze-radar yezigaba ezinezigaba zihlanganisa amandla aphezulu aphezulu nokusebenza kwe-wideband, okwenza ukunciphisa kwe-PIM kubaluleke kakhulu ukuze kutholwe okuqondiwe okubuthakathaka.

Ukuhlaziywa Komphumela Wokusebenza

Ukufakwa kwensimu kubonisa ukuthi ukunciphisa i-PIM kusuka ku--125 dBc kuya ku--150 dBc kuthuthukisa ukuzwela kwe-receiver yesiteshi sesisekelo ngo-3 kuya ku-5 dB, okuhumusha ngqo ku-radius yokumboza ende noma ukungena kwesakhiwo okuthuthukisiwe. Eziteshini zomhlaba zesathelayithi, ukusebenza kwe-PCB ye-PIM okuphansi kakhulu kwenza kube lula ukusebenza ngama -antenna amancane noma amandla okudlulisa ancishisiwe ngenkathi kugcinwa imingcele yezixhumanisi. Izinhlelo ze-radar ziyazuza ekwenqatshweni okuthuthukisiwe kwe-clutter kanye nokubandlululwa okuqondiwe lapho izimpendulo ezingamanga zingasafihli ukubuyiselwa kwangempela.

Idizayini yokuhlanganisa amasu

Ukuqaliswa okuyimpumelelo okuphansi kwe-PIM kudlulela ngalé kwedizayini ngayinye ye-PCB ukuze kuhlanganiswe ukwakheka kwemojuli ye-RF ephelele. Amanethiwekhi okuphakelayo kwe-antenna azuza kuma tees ahlanganisiwe wokuchema nokuhlunga okusetshenziswa ngezinhlaka zolayini wokudlulisa we-PIM ophansi. Ukuhlaziywa kwezinga lesistimu kuhlonza iminikelo ye-PIM eqongelelekayo evela emihlanganweni eminingi, ukwaba amabhajethi kumamojula ngamanye ngokusekelwe endaweni yawo ochungechungeni lwesignali kanye namazinga wamandla okusebenza.

Isiphetho

Idizayini ephansi ye-PIM PCB imele isiyalo sobunjiniyela esihlelekile esihlanganisa isayensi yezinto, ithiyori kagesi, kanye nokukhiqizwa okunembayo ukuze kuqedwe imithombo yokuphazamiseka engaqondile kumasistimu amafrikhwensi aphezulu. Njengoba ingqalasizinda engenazintambo iguqukela kumaza aphezulu, imingcele ebanzi, kanye nokukhula kwesiteshi, ukunciphisa i-PIM kuba bucayi kakhulu. Ukuqaliswa okuyimpumelelo kudinga ukunakwa kuzo zonke izici zokutholwa kwe-PCB, kusukela ekukhethweni kwezinto ezibonakalayo kuya ezinqubweni zokugcina zokuhlanganisa.

I-Highleap Electronics iletha izixazululo eziphelele ze-PIM PCB eziphansi ngokusebenzisa:

• Ukukhetha izinto ezithuthukile – Ama-laminate aphansi okulahlekelwa afaka phakathi i-laminate ekhethekile ephansi okulahlekelwa kanye ne-PTFE substrates enamaphrofayili ongaphezulu ethusi alawulwayo
• Ukuqedwa kwendawo elungiselelwe - Izinketho zokucwenga zamahhala ze-nickel (EPIG, isiliva lokucwiliswa) ezisusa ukuxhumana kwe-ferromagnetic
• Ukukhiqiza okunembayo - Izinqubo zokucwenga ezilawulwayo, izindawo zokuhlangana ezingangcolisi, kanye nokufakwa kwesixhumi esishiwo ngetorque
• Amaphrothokholi okuhlola aqinile - Ukuqinisekiswa kwe-PIM kuzo zonke izigaba zefrikhwensi yokusebenza ngokuhamba ngebhayisikili lokushisa kanye nokulawula inqubo yezibalo
• Ukubambisana kwezobunjiniyela - Ukusekelwa kwedizayini kokwenza kahle isitaki, ukucaciswa kwezinto ezibonakalayo, nokuqinisekisa ukusebenza

Xhumana nethimba lethu lobunjiniyela ukuze uxoxe ngezidingo zakho ze-PCB eziphansi ze-PIM futhi ufunde ukuthi izinqubo zethu zokukhiqiza eziqinisekisiwe zingakusekela kanjani ukuthuthukiswa kohlelo lwakho lwe-RF lwesizukulwane esilandelayo.