Cov xov hlau coaxial siv los xa cov zog RF los ntawm ib qho chaw nres nkoj lossis cov khoom siv mus rau lwm qhov chaw nres nkoj / qhov chaw ntawm lub kaw lus. Cov xov hlau coaxial txheem siv ua kab microwave coaxial. Daim ntawv no ntawm cov hlau feem ntau muaj ob lub conductors hauv ib lub cylindrical zoo li nyob ib puag ncig ib qho axis. Lawv txhua tus raug sib cais los ntawm cov khoom siv dielectric. Ntawm cov zaus qis dua, daim ntawv polyethylene siv ua dielectric, thiab ntawm cov zaus siab dua Teflon khoom siv.
Hom kab hlau coaxial
Muaj ntau hom coaxial cable nyob ntawm seb tus neeg xa hluav taws xob tsim thiab cov txheej txheem tiv thaiv siv. Cov hom coaxial cable suav nrog tus qauv coaxial cable raws li tau piav qhia saum toj no nrog rau cov roj-filled coaxial cable, articulated coaxial cable, thiab bi-wire shielded coaxial cable.
Cov xov hlau coaxial uas yoog tau yog siv rau hauv cov kav hlau txais xov tooj cua tshaj tawm hauv TV nrog cov xov hlau sab nraud ua los ntawm ntawv ci lossis braid.
Ntawm cov zaus microwave, tus conductor sab nraud yog rigid thiab dielectric yuav solid. Hauv cov cables coaxial uas muaj roj, tus conductor nruab nrab yog ua los ntawm cov insulator ceramic nyias, kuj siv polytetrafluoroethylene. Cov nitrogen qhuav tuaj yeem siv ua cov khoom siv dielectric.
Hauv articulated coax, lub insulator sab hauv yog tsa nyob ib puag ncig lub conductor sab hauv. nyob ib puag ncig lub shielded conductor thiab nyob ib puag ncig no insulating sheath.
Hauv cov xov hlau coaxial uas muaj ob txheej tiv thaiv, feem ntau muaj ob txheej tiv thaiv los ntawm kev muab ib txheej tiv thaiv sab hauv thiab ib txheej tiv thaiv sab nraud. Qhov no tiv thaiv cov teeb liab los ntawm EMI thiab txhua yam hluav taws xob los ntawm cov xov hlau uas cuam tshuam rau cov kab ke nyob ze.
Cov yam ntxwv ntawm kab coaxial impedance
Tus yam ntxwv impedance ntawm cov cable coaxial yooj yim tuaj yeem txiav txim siab siv cov mis hauv qab no.
Zo = 138/sqrt(K) * Log(D/d) Ohms
nyob rau hauv,
K yog qhov dielectric constant ntawm lub insulator ntawm cov conductors sab hauv thiab sab nraud. D yog txoj kab uas hla ntawm cov conductor sab nraud thiab d yog txoj kab uas hla ntawm cov conductor sab hauv.
Cov Zoo Los Yog Cov Zoo ntawm Coaxial Cable
Cov txiaj ntsig lossis qhov zoo ntawm coaxial cable hauv qab no:
➨Vim yog qhov cuam tshuam ntawm daim tawv nqaij, cov xov hlau coaxial siv rau hauv cov ntawv thov zaus siab (> 50 MHz) siv cov tooj liab cladding ntawm tus neeg xyuas pib nruab nrab. Qhov cuam tshuam ntawm daim tawv nqaij yog qhov tshwm sim ntawm cov teeb liab zaus siab kis mus rau sab nraud ntawm tus neeg xyuas pib. Nws ua rau lub zog tensile ntawm lub cable nce thiab txo qhov hnyav.
➨Coaxial cable pheej yig dua.
➨Tus neeg coj sab nraud hauv coaxial cable yog siv los txhim kho kev txo qis thiab kev tiv thaiv. Qhov no ua tiav los ntawm kev siv cov ntawv ci thib ob lossis braid hu ua lub sheath (xaiv C2 hauv Daim Duab 1). Lub tsho ua haujlwm ua lub tsho tiv thaiv ib puag ncig thiab ua rau hauv cov coaxial cable ua ib qho hluav taws kub retardant.
Nws tsis tshua muaj kev cuam tshuam rau suab nrov lossis kev cuam tshuam (EMI lossis RFI) dua li cov xov hlau sib txuas.
➨Piv nrog cov khub sib ntswg, nws txhawb nqa kev xa xov tooj cua siab.
➨Yooj yim rau xaim thiab nthuav dav vim muaj kev ywj pheej.
➨Nws tso cai rau kev sib kis siab, coaxial cable muaj cov khoom tiv thaiv zoo dua.
Qhov Tsis Zoo Los Yog Qhov Tsis Zoo ntawm Coaxial Cable
Cov kev tsis zoo ntawm coaxial cable yog cov hauv qab no:
➨Loj heev.
➨Kev teeb tsa ntev yog kim vim nws tuab thiab tawv.
➨Vim tias ib txoj hlua siv los xa cov teeb liab thoob plaws hauv lub network, yog tias ib txoj hlua tsis ua haujlwm, tag nrho lub network yuav poob qis.
Kev ruaj ntseg yog qhov txhawj xeeb loj vim tias nws yooj yim rau kev mloog cov xov hlau coaxial los ntawm kev rhuav nws thiab ntxig T-connector (hom BNC) ntawm ob qho.
➨Yuav tsum tau grounded kom tiv thaiv kev cuam tshuam.
Lub sijhawm tshaj tawm: Lub Kaum Ob Hlis-15-2023
