Coaxial cable yog siv los xa RF zog los ntawm ib qho chaw nres nkoj lossis cov khoom siv mus rau lwm qhov chaw nres nkoj / qhov chaw ntawm lub cev. Txheem coaxial cable yog siv los ua microwave coaxial kab. Daim ntawv ntawm cov hlau no feem ntau muaj ob lub conductors nyob rau hauv ib tug cylindrical zoo nyob ib ncig ntawm ib tug axis. Lawv tag nrho yog cais los ntawm cov khoom siv dielectric. Ntawm qhov tsawg zaus, ib daim ntawv polyethylene yog siv los ua dielectric, thiab cov khoom siv Teflon ntau dua yog siv.
Hom ntawm coaxial cable
Muaj ntau hom coaxial cable nyob ntawm seb tus neeg xyuas pib siv thiab thaiv txoj kev siv. Coaxial cable hom muaj xws li cov qauv coaxial cable raws li tau piav qhia saum toj no nrog rau cov roj puv coaxial cable, articulated coaxial cable, thiab bi-wire shielded coaxial cable.
Flexible coaxial cables yog siv nyob rau hauv TV tshaj tawm xov xwm tau txais cov kav hlau txais xov nrog cov neeg xyuas sab nrauv uas ua los ntawm cov ntawv ci lossis braid.
Ntawm microwave frequencies, tus neeg xyuas pib sab nraud yog nruj thiab cov dielectric yuav yog khoom. Hauv cov pa roj carbon monoxide coaxial cables, tus neeg xyuas pib hauv nruab nrab yog ua los ntawm cov khoom siv hluav taws xob nyias nyias, kuj siv polytetrafluoroethylene. Cov nitrogen qhuav tuaj yeem siv los ua cov khoom siv dielectric.
Nyob rau hauv articulated coax, lub puab insulator yog tsa nyob ib ncig ntawm lub puab conductor. nyob ib ncig ntawm lub shielded conductor thiab nyob ib ncig ntawm no tiv thaiv insulating sheath.
Nyob rau hauv ob-shielded coaxial cable, ob txheej ntawm kev tiv thaiv feem ntau yog muab los ntawm kev muab ib daim ntaub thaiv sab hauv thiab ib daim ntaub thaiv npog. Qhov no tiv thaiv lub teeb liab los ntawm EMI thiab ib qho hluav taws xob los ntawm cable cuam tshuam rau cov kab ke nyob ze.
Coaxial kab yam ntxwv impedance
Cov yam ntxwv impedance ntawm ib qho yooj yim coaxial cable tuaj yeem txiav txim siab siv cov qauv hauv qab no.
Zo = 138/sqrt(K) * Log(D/d) Ohms
hauv,
K yog qhov dielectric tas li ntawm cov insulator ntawm sab hauv thiab sab nraud conductors. D yog txoj kab uas hla ntawm tus neeg xyuas pib thiab d yog txoj kab uas hla ntawm tus neeg xyuas pib.
Qhov zoo lossis qhov zoo ntawm Coaxial Cable
Hauv qab no yog qhov zoo lossis qhov zoo ntawm coaxial cable:
➨Vim cov nyhuv ntawm daim tawv nqaij, coaxial cables siv nyob rau hauv high zaus daim ntawv thov (> 50 MHz) siv tooj liab cladding ntawm qhov chaw conductor. Cov nyhuv ntawm daim tawv nqaij yog tshwm sim los ntawm cov teeb liab ntau zaus propagating raws sab nrauv ntawm tus neeg xyuas pib. Nws ua kom lub zog tensile ntawm lub cable thiab txo qhov hnyav.
➨ Coaxial cable raug nqi tsawg dua.
➨ Cov neeg xyuas pib sab nrauv hauv coaxial cable yog siv los txhim kho kev sib tw thiab kev tiv thaiv. Qhov no yog ua tiav los ntawm kev siv cov ntawv ci thib ob los yog braid hu ua sheath (tsim C2 hauv daim duab 1). Lub tsho ua haujlwm ua ib qho chaw tiv thaiv ib puag ncig thiab ua rau hauv ib qho coaxial cable raws li cov nplaim hluav taws.
➨ Nws tsis tshua muaj suab nrov lossis cuam tshuam (EMI lossis RFI) dua li cov hlua txuas txuas.
➨ Piv nrog twisted khub, nws txhawb high-bandwidth teeb liab kis tau tus mob.
➨ Yooj yim rau xaim thiab nthuav dav vim yooj yim.
➨ Nws tso cai rau kev sib kis tau zoo, coaxial cable muaj cov ntaub thaiv zoo dua.
Qhov tsis zoo lossis qhov tsis zoo ntawm Coaxial Cable
Cov hauv qab no yog qhov tsis zoo ntawm coaxial cable:
➨ Loj loj.
➨ Kev teeb tsa ntev yog kim vim nws cov tuab thiab tawv.
➨ Txij li thaum ib lub cable siv los xa cov teeb liab thoob plaws hauv lub network, yog tias ib lub cable tsis ua haujlwm, tag nrho lub network yuav poob.
➨ Kev ruaj ntseg yog ib qho kev txhawj xeeb loj vim nws yooj yim rau kev mloog ntawm lub coaxial cable los ntawm kev tawg nws thiab ntxig rau T-connector (BNC hom) ntawm ob.
➨ Yuav tsum tau ua hauv av kom tsis txhob cuam tshuam.
Post lub sij hawm: Dec-15-2023
