Lub kav hlau txais xov isotropic yog ib qho chaw siv tau zoo tshaj plaws uas tso tawm lub zog electromagnetic sib npaug zos rau txhua qhov kev taw qhia. Cov kws ua haujlwm siv nws los sib piv lub zog ntawm lub kav hlau txais xov, kev coj ua thiab lub zog hluav taws xob, txawm tias lub kav hlau txais xov isotropic zoo meej tsis tuaj yeem tsim tau hauv kev xyaum.
Phau ntawv qhia no piav qhia txog lub ntsiab lus ntawm isotropic radiation, cov duab ntawm ib qho isotropic radiation pattern, vim li cas qhov nce ntawm qhov siv yog 0 dBi, thiab yuav siv tib qho siv li cas hauv kev xam EIRP.
Lub Antenna Isotropic yog dab tsi?
Ib lub kav hlau txais xov isotropic, tseem hu ua isotropic radiator, yog ib qho chaw theoretical nrog tib lub zog hluav taws xob rau txhua azimuth thiab lub kaum sab xis. Nws tsis muaj kev taw qhia nyiam thiab yog li ntawd muab lub hauv paus nruab nrab rau kev piav qhia txog tus cwj pwm ntawm cov kav hlau txais xov tiag tiag.
- Nws yog ib qho kev siv lej zoo tagnrho, tsis yog lub kav hlau txais xov uas ua tau tiag tiag.
- Nws lub zog hluav taws xob yog qhov ruaj khov thoob plaws lub kaum sab xis khov kho nyob ib puag ncig qhov chaw.
- Nws qhov kev taw qhia yog 1, uas yog 0 dBi.
- Qhov nce ntawm lub kav hlau txais xov uas siv tau hais hauv dBi yog ntsuas piv rau qhov siv no.
Tus Qauv Hluav Taws Xob Isotropic Zoo Li Cas?
Tus qauv hluav taws xob isotropic peb-seem zoo tagnrho yog lub voos xwmfab uas nyob nruab nrab ntawm qhov chaw. Txhua lub ntsiab lus ntawm lub voos xwmfab ntawd sawv cev rau tib lub zog hluav taws xob ntawm tib qhov deb. Txhua lub dav hlau ob-seem uas hla dhau qhov chaw nruab nrab tsim cov qauv voj voog.
Tus qauv kheej kheej no ua rau lub isotropic radiator muaj txiaj ntsig zoo hauv kev tshawb fawb ntawm lub antenna: nws muab qib hluav taws xob nruab nrab uas lub antenna tiag tiag tuaj yeem piv rau. Lub antenna siv tau yeej ib txwm muaj cov qauv lub cev, kev npaj pub thiab ib puag ncig uas ua rau muaj kev hloov pauv ntawm kev taw qhia, yog li nws cov qauv ntsuas yuav muaj cov lobes tseem ceeb, cov lobes sab thiab cov nulls.
Qauv siv:Hauv peb qhov ntev, cov hluav taws xob isotropic yog spherical. Cov hluav taws xob omnidirectional tsuas yog sib xws nyob ib puag ncig lub dav hlau xaiv.
Qhov sib txawv tseem ceeb:tus qauv isotropic spherical tsis zoo ib yam li tus qauv donut uas feem ntau cuam tshuam nrog dipole thiab lwm yam omnidirectional antennas.
Daim duab qhia saum toj no qhia txog tus qauv omnidirectional, zoo li dipole: zoo ib yam li azimuth, zoo li donut hauv peb qhov ntev thiab zoo li daim duab yim hauv kev txiav ntsug. Nws muaj txiaj ntsig zoo rau kev sib piv, tab sis nws tsis yog tus qauv spherical ntawm lub isotropic radiator.
Isotropic vs. Omnidirectional Antenna
Cov lus isotropic thiab omnidirectional qee zaum siv tsis hnyav, tab sis lawv piav qhia txog tus cwj pwm hluav taws xob sib txawv.
- Lub kav hlau txais xov isotropic:nws ci ntsa iab sib npaug zos rau txhua qhov kev taw qhia hauv peb qhov ntev. Nws yog ib qho kev siv theoretical nrog ib lub qauv spherical.
- Lub kav hlau txais xov omnidirectional:nws tawm tsam kwv yees li sib npaug zos nyob ib puag ncig ib lub dav hlau siv, feem ntau yog lub dav hlau kab rov tav azimuth, thaum nws cov hluav taws xob hloov pauv raws li qhov siab.
- Tus qauv omnidirectional ib txwm muaj:lub voj voog hauv lub dav hlau kab rov tav thiab lub duab yim hauv lub dav hlau ntsug, tsim kom muaj tus qauv peb sab zoo li lub donut.
Lub kav hlau txais xov omnidirectional yuav muab kev pab them nqi 360-degree azimuth, tab sis nws tsis yog isotropic vim tias nws feem ntau muaj cov hluav taws xob tsis muaj zog lossis nulls raws nws txoj kab.
Vim li cas Isotropic Antenna thiaj nce 0 dBi?
Lub radiator isotropic zoo tagnrho muaj qhov directivity ntawm 1 vim nws tsis concentrate lub zog rau hauv txhua qhov kev taw qhia. Qhia rau ntawm qhov ntsuas logarithmic, qhov kev siv no yog:
10 cav10(1) = 0 dBi
Lub tom kawg "i" txhais tau hais tias tus nqi yog hais txog lub isotropic radiator. Lub antenna tiag tiag uas ntsuas ntawm 3 dBi tsim tawm kwv yees li ob npaug ntawm lub zog ceev hauv nws qhov kev taw qhia siab tshaj plaws piv rau qhov isotropic siv thaum qhov kev sib piv siv tib lub zog lees txais. Nws tsis txhais tau hais tias lub isotropic radiator nws tus kheej muaj 3 dBi nce.
Yog xav paub txog cov ntsiab lus tseem ceeb, mus saibkev taw qhia ntawm lub kav hlau txais xovthiabantenna efficiency thiab nce.
EIRP Siv Isotropic Reference Li Cas
Lub zog sib npaug isotropically radiated, lossis EIRP, qhia txog lub zog uas lub radiator isotropic zoo tagnrho yuav tsum tau tsim kom muaj tib lub zog ceev tshaj plaws li lub kaw lus xa xov tiag tiag hauv ib qho kev taw qhia tshwj xeeb. Hauv cov chav logarithmic:
EIRP (dBm) = lub zog xa tawm (dBm) + qhov nce ntawm lub kav hlau txais xov (dBi) - qhov poob ntawm cov khoom noj (dB)
Qhov kev sib raug zoo no muab cov zis ntawm lub transmitter, qhov nce ntawm lub antenna piv rau isotropic thiab kev poob los ntawm cov cables, connectors lossis lwm yam khoom pub. Yog li ntawd, EIRP yog ib qho ntau ntawm qhov system, tsis yog lub zog ntxiv uas lub antenna tsim tawm.
ERP piv rau EIRP
EIRP siv lub isotropic radiator ua nws qhov kev siv. Lub zog hluav taws xob zoo, lossis ERP, siv ib nrab nthwv dej dipole ua nws qhov kev siv. Ib nrab nthwv dej dipole zoo tagnrho muaj kwv yees li 2.15 dBi nce hauv nws qhov kev taw qhia hluav taws xob siab tshaj plaws, yog li ob qhov ntau sib txawv los ntawm 2.15 dB.
ERP (dBW) = EIRP (dBW) - 2.15 dB
Piv txwv li, ib lub tshuab uas muaj EIRP ntawm 30 dBW muaj ERP ntawm 27.85 dBW. Ib txwm xyuas seb lub antenna lossis kev txwv tsis pub tshaj tawm puas tau teev nyob rau hauv dBi/dBW EIRP lossis dBd/dBW ERP ua ntej piv cov nqi.
Yuav kom nkag siab tias cov antennas tiag tiag faib lub zog rau hauv lobes thiab nulls li cas, txuas ntxiv nrog peb phau ntawv qhia raucov qauv hluav taws xob ntawm lub antenna.
Cov Lus Qhia Txog Kev Siv Tau
- Lub kav hlau txais xov isotropic yog qhov chaw siv tau zoo tshaj plaws, tsis yog qhov tsim kav hlau txais xov uas siv tau tiag tiag.
- Nws cov qauv hluav taws xob peb-seem yog lub voj voog, thiab txhua qhov txiav ob-seem hauv nruab nrab yog lub voj voog.
- Nws qhov kev coj ua piv txwv thiab qhov nce yog 1, lossis 0 dBi.
- Lub kav hlau txais xov omnidirectional tsuas yog sib xws hauv ib lub dav hlau xaiv thiab feem ntau muaj cov qauv peb-seem zoo li lub donut.
- EIRP yog hais txog isotropic gain, thaum ERP yog hais txog ib nrab-wave dipole.
RF MISO muab cov kav hlau txais xov uas muaj kev taw qhia thiab dav dav rau kev ntsuas microwave, kev sib txuas lus thiab kev koom ua ke ntawm lub kaw lus. Tshawb nrhiav peb covKev daws teeb meem ntawm omnidirectional antenna or tiv tauj peb pab neeglos tham txog koj qhov kev xav tau ntawm kev ua haujlwm zaus, qhov nce, polarization thiab interface.
Lub sijhawm tshaj tawm: Plaub Hlis-17-2026
