Izindaba

Izingxenye ze-Passive kuma-RF Circuits 

Ama-resistors, ama-capacitor, ama-Antenna. . . . Funda mayelana nezingxenye ze-passive ezisetshenziswa kumasistimu e-RF.

Amasistimu e-RF awahlukile kakhulu kwezinye izinhlobo zamasekhethi kagesi. Imithetho efanayo yefiziksi iyasebenza, futhi ngenxa yalokho izingxenye eziyisisekelo ezisetshenziswa kumiklamo ye-RF nazo zitholakala kumasekhethi edijithali namasekhethi e-analog anemvamisa ephansi.

Nokho, ukwakheka kwe-RF kuhilela isethi eyingqayizivele yezinselele nezinjongo, futhi ngenxa yalokho izici nokusetshenziswa kwezingxenye kudinga ukucatshangelwa okukhethekile lapho sisebenza kumongo we-RF. Futhi, amanye amasekhethi ahlanganisiwe enza umsebenzi ocace kakhulu ezinhlelweni ze-RF—awasetshenziswa kumasekhethi anefrikhwensi encane futhi angase angaqondwa kahle yilabo abanolwazi oluncane ngamasu okuklama e-RF.

Sivame ukuhlukanisa izingxenye ngokuthi ezisebenzayo noma ezingenzi lutho, futhi le ndlela isebenza ngokulinganayo endaweni ye-RF. Lezi zindaba zidingida izingxenye ze-passive ikakhulukazi maqondana namasekhethi e-RF, futhi ikhasi elilandelayo lihlanganisa izingxenye ezisebenzayo.

Ama-Capacitors

I-capacitor ekahle izohlinzeka ngokusebenza okufanayo ncamashi kwesignali engu-1 Hz kanye nesignali engu-1 GHz. Kepha izakhi azikaze zilunge, futhi izinto ezingezinhle ze-capacitor zingabaluleka kakhulu kumafrikhwensi aphezulu.

"C" ihambisana ne-capacitor ekahle engcwatshwe phakathi kwezakhi eziningi ze-parasitic. Sinokumelana okungapheli phakathi kwamapuleti (i-RD), ukumelana nochungechunge (RS), i-series inductance (LS), kanye ne-parallel capacitance (CP) phakathi kwamaphedi e-PCB nendiza yaphansi (sithatha izingxenye ezikhuphuka phezulu; okwengeziwe ngalokhu kamuva).

Okubaluleke kakhulu okungeyona i-unideality uma sisebenza ngamasignali wemvamisa ephezulu i-inductance. Silindele ukuthi i-impedance ye-capacitor yehle ngokungapheli njengoba imvamisa inyuka, kodwa ukuba khona kwe-parasitic inductance kubangela ukuthi i-impedance icwiliswe phansi ku-self-resonant frequency bese iqala ukwanda:

Ama-resistors, et al.

Ngisho nezinto ezimelana nazo zingaba nzima kumafrikhwensi aphezulu, ngoba zine-series inductance, i-parallel capacitance, namandla ajwayelekile ahlotshaniswa namaphedi e-PCB.

Futhi lokhu kuveza iphuzu elibalulekile: uma usebenza ngamaza aphezulu, izakhi zesekethe ye-parasitic zikuyo yonke indawo. Akunandaba ukuthi into ephikisayo ilula noma ilungile kangakanani, isadinga ukupakishwa futhi ithengiswe ku-PCB, futhi umphumela kuba yizinambuzane. Okufanayo kusebenza kunoma iyiphi enye ingxenye: uma ihlanganiswe futhi ithengiswa ebhodini, izakhi ze-parasitic zikhona.

Amakristalu

Ingqikithi ye-RF ixhaphaza amasignali amaza aphezulu ukuze adlulisele ulwazi, kodwa ngaphambi kokuthi sikhohlise kudingeka senze. Njengakwezinye izinhlobo zamasekhethi, amakristalu ayindlela eyisisekelo yokukhiqiza ireferensi ezinzile.

Kodwa-ke, ekwakhiweni kwesignali yedijithali kanye nengxubevange, kuvame ukuvela ukuthi amasekhethi asuselwa kukristalu empeleni awadingi ukunemba okungahlinzekwa yikristalu, futhi ngenxa yalokho kulula ukunganaki mayelana nokukhethwa kwekristalu. Isekhethi ye-RF, ngokuphambene, ingaba nezidingo eziqinile zamafrikhwensi, futhi lokhu akudingi nje kuphela ukunemba kwamafrikhwensi okuqala kodwa nokuzinza kwamafrikhwensi.

Imvamisa ye-oscillation yekristalu evamile izwela ukuhlukahluka kwezinga lokushisa. Umphumela wokungaqini kahle kwefrikhwensi kudala izinkinga ezinhlelweni ze-RF, ikakhulukazi amasistimu azochayeka ekuhlukeni okukhulu kwezinga lokushisa elizungezile. Ngakho-ke, uhlelo lungadinga i-TCXO, okungukuthi, i-crystal oscillator enezinga lokushisa. Lawa madivayisi ahlanganisa ukujikeleza okunxephezela ukuhluka kwefrikhwensi yekristalu:

Izimpondo

I-antenna iyingxenye ye-passive esetshenziselwa ukuguqula isignali kagesi ye-RF ibe emisebeni ye-electromagnetic (EMR), noma ngokuphambene nalokho. Ngezinye izingxenye kanye nama-conductor sizama ukunciphisa imiphumela ye-EMR, futhi ngezinti sizama ukuthuthukisa ukukhiqizwa noma ukwamukela kwe-EMR ngokuphathelene nezidingo zesicelo.

Isayensi ye-antenna ayilula neze. Izici ezahlukahlukene zithonya inqubo yokukhetha noma yokuklama uthi olulungele uhlelo oluthile. I-AAC inezindatshana ezimbili (chofoza lapha nalapha) ezinikeza isingeniso esihle kakhulu semiqondo ye-antenna.

Amafrikhwensi aphezulu ahambisana nezinselelo zemiklamo ehlukahlukene, nakuba ingxenye ye-antenna yohlelo ingaba yinkinga kangako njengoba imvamisa inyuka, ngoba amaza aphezulu avumela ukusetshenziswa kwezinti ezimfishane. Namuhla sekuvamile ukusebenzisa “i-antenna ye-chip,” edayiswa ku-PCB njengezinto ezijwayelekile zokukhweza phezulu, noma uthi lwe-PCB, oludalwe ngokuhlanganisa umkhondo oklanywe ngokukhethekile esakhiweni se-PCB.

Isifinyezo

Ezinye izingxenye zivamile ezinhlelweni ze-RF kuphela, kanti ezinye kufanele zikhethwe futhi zisetshenziswe ngokucophelela ngenxa yokuziphatha kwazo okungafanelekile kwamaza aphezulu.

Izingxenye ze-Passive zikhombisa impendulo yemvamisa engafanele ngenxa ye-parasitic inductance namandla.

Izinhlelo zokusebenza ze-RF zingadinga amakristalu anembe kakhudlwana kanye/noma azinzile kunamakristalu avame ukusetshenziswa kumasekhethi edijithali.

Ama-antenna ayizingxenye ezibalulekile okufanele zikhethwe ngokwezimpawu nezidingo zohlelo lwe-RF.

Si Chuan Keenlion Microwave ukukhetha okukhulu ekucushweni kwe-narrowband ne-broadband, okumboza amaza asuka ku-0.5 kuye ku-50 GHz. Zenzelwe ukuphatha amandla okufaka ama-watts asuka ku-10 kuye kwangama-30 kusistimu yokudlulisa engu-50-ohm. Imiklamo ye-Microstrip noma ye-stripline isetshenziswa, futhi yenzelwe ukusebenza kahle kakhulu.

Singakwazi futhi ukwenza ngokwezifiso izingxenye ze-rf passive ngokuya ngezidingo zakho. Ungafaka ikhasi lokwenza ngokwezifiso ukuze unikeze imininingwane oyidingayo.