Cov kws tshaj lij hluav taws xob paub tias cov kav hlau txais xov xa thiab tau txais cov cim hauv daim ntawv ntawm nthwv dej ntawm electromagnetic (EM) lub zog piav qhia los ntawm Maxwell qhov sib npaug. Raws li nrog ntau lub ntsiab lus, cov kev sib npaug, thiab kev nthuav tawm, cov khoom ntawm electromagnetism, tuaj yeem kawm ntawm ntau qib, los ntawm cov ntsiab lus zoo mus rau qhov sib npaug.
Muaj ntau ntau yam rau electromagnetic zog propagation, ib qho ntawm cov polarization, uas muaj peev xwm muaj ntau yam kev cuam tshuam los yog kev txhawj xeeb nyob rau hauv daim ntawv thov thiab lawv cov kav hlau txais xov tsim. Lub hauv paus ntsiab lus ntawm polarization siv rau tag nrho cov hluav taws xob hluav taws xob, suav nrog RF / wireless, optical zog, thiab feem ntau siv hauv kev siv kho qhov muag.
Kav hlau txais xov polarization yog dab tsi?
Ua ntej nkag siab txog polarization, peb yuav tsum xub nkag siab cov ntsiab cai ntawm electromagnetic nthwv dej. Cov nthwv dej no yog tsim los ntawm hluav taws xob (E fields) thiab magnetic fields (H fields) thiab txav mus rau hauv ib qho kev taw qhia. E thiab H teb yog nyob rau ib leeg thiab mus rau kev taw qhia ntawm dav hlau nthwv dej propagation.
Polarization yog hais txog E-field dav hlau los ntawm qhov kev xav ntawm lub teeb liab transmitter: rau kab rov tav polarization, hluav taws xob teb yuav txav mus rau sab hauv lub dav hlau kab rov tav, thaum rau ntsug polarization, hluav taws xob teb yuav oscillate nce thiab nqis hauv lub dav hlau ntsug. duab 1).
Daim duab 1: Electromagnetic zog nthwv dej muaj xws li kev sib nrig sib perpendicular E thiab H teb Cheebtsam
Linear polarization thiab ncig polarization
Polarization hom muaj xws li cov hauv qab no:
Nyob rau hauv qhov yooj yim linear polarization, ob qhov polarizations tau yog orthogonal (perpendicular) rau ib leeg (Daim duab 2). Nyob rau hauv txoj kev xav, kab rov tav polarized txais kav hlau txais xov yuav tsis "pom" lub teeb liab los ntawm vertically polarized kav hlau txais xov thiab vice versa, txawm tias ob qho tib si ua haujlwm ntawm tib zaus. Qhov zoo dua lawv ua raws, qhov teeb liab ntau dua yog ntes, thiab lub zog hloov pauv yog qhov loj tshaj thaum polarizations phim.
Daim duab 2: Linear polarization muab ob txoj kev xaiv polarization ntawm txoj cai kaum rau ib leeg
Lub oblique polarization ntawm tus kav hlau txais xov yog ib hom kab polarization. Zoo li cov kab rov tav thiab ntsug polarization yooj yim, qhov polarization no tsuas yog ua rau muaj kev nkag siab zoo hauv thaj chaw hauv av. Oblique polarization yog ntawm lub kaum sab xis ntawm ± 45 degrees rau kab rov tav siv dav hlau. Thaum qhov no tsuas yog lwm daim ntawv ntawm cov kab polarization, lo lus "linear" feem ntau tsuas yog hais txog kab rov tav lossis vertically polarized antennas.
Txawm hais tias qee qhov poob, cov cim xa (los yog tau txais) los ntawm kab pheeb ces kaum kav hlau txais xov yog ua tau nrog tsuas yog kab rov tav lossis ntsug polarized kav hlau txais xov. Obliquely polarized kav hlau txais xov muaj txiaj ntsig zoo thaum lub polarization ntawm ib lossis ob lub kav hlau txais xov tsis paub lossis hloov pauv thaum siv.
Circular polarization (CP) yog qhov nyuaj tshaj li linear polarization. Nyob rau hauv hom no, lub polarization sawv cev los ntawm E teb vector rotates raws li lub teeb liab propagates. Thaum tig mus rau sab xis (saib tawm ntawm lub transmitter), lub voj voog polarization yog hu ua right-handed circular polarization (RHCP); Thaum tig mus rau sab laug, sab laug-tes ncig polarization (LHCP) (Daim duab 3)
Daim duab 3: Nyob rau hauv lub voj voog polarization, E field vector ntawm electromagnetic yoj tig; qhov kev sib hloov no tuaj yeem yog sab xis lossis sab laug
Lub teeb liab CP muaj ob lub suab orthogonal uas tawm ntawm theem. Peb cov xwm txheej yuav tsum tsim kom muaj CP teeb liab. Lub teb E yuav tsum muaj ob qho tib si orthogonal; ob lub Cheebtsam yuav tsum yog 90 degrees tawm ntawm theem thiab sib npaug hauv amplitude. Ib txoj hauv kev yooj yim los tsim CP yog siv lub kav hlau txais xov helical.
Elliptical polarization (EP) yog ib hom CP. Elliptically polarized nthwv dej yog qhov nce uas tsim los ntawm ob kab polarized nthwv dej, zoo li CP nthwv dej. Thaum ob qho tib si perpendicular linearly polarized nthwv dej uas tsis sib xws amplitudes raug ua ke, ib qho elliptical polarized nthwv dej yog tsim.
Lub polarization mismatch ntawm tus kav hlau txais xov yog piav qhia los ntawm polarization poob yam (PLF). Qhov kev ntsuas no tau qhia hauv decibels (dB) thiab yog ib qho kev ua haujlwm ntawm qhov sib txawv ntawm lub kaum sab xis ntawm lub xaim thiab txais cov kav hlau txais xov. Txoj kev xav, PLF tuaj yeem nyob ntawm 0 dB (tsis poob) rau lub kav hlau txais xov zoo kawg nkaus rau infinite dB (tsis kawg) rau lub kav hlau txais xov orthogonal zoo kawg nkaus.
Hauv kev muaj tiag, txawm li cas los xij, kev sib haum xeeb (lossis misalignment) ntawm polarization tsis zoo tag nrho vim tias txoj haujlwm ntawm tus kav hlau txais xov, cov neeg siv tus cwj pwm, kev cuam tshuam ntawm cov channel, kev cuam tshuam ntau yam, thiab lwm yam tshwm sim tuaj yeem ua rau qee qhov kev cuam tshuam ntawm kev sib kis ntawm electromagnetic teb. Thaum xub thawj, yuav muaj 10 - 30 dB lossis ntau dua ntawm cov teeb liab hla-polarization "tawg" los ntawm orthogonal polarization, uas qee zaum yuav txaus los cuam tshuam nrog kev rov qab los ntawm cov teeb liab xav tau.
Hauv qhov sib piv, qhov tseeb PLF rau ob lub kav hlau txais xov zoo sib xws nrog cov polarization zoo tshaj plaws yuav yog 10 dB, 20 dB, lossis ntau dua, nyob ntawm qhov xwm txheej, thiab tuaj yeem cuam tshuam cov teeb liab rov qab. Hauv lwm lo lus, kev tsis xav hla-polarization thiab PLF tuaj yeem ua haujlwm ob qho tib si los ntawm kev cuam tshuam nrog lub teeb liab xav tau lossis txo cov teeb liab xav tau.
Vim li cas ho txhawj txog polarization?
Polarization ua hauj lwm nyob rau hauv ob txoj kev: qhov ntau dlhos ob lub kav hlau txais xov thiab muaj tib lub polarization, qhov zoo dua lub zog ntawm cov teeb liab tau txais. Hloov pauv, kev sib raug zoo polarization tsis zoo ua rau nws nyuaj rau cov neeg txais, txawm tias xav tau lossis tsis txaus siab, kom ntes txaus ntawm cov teeb liab ntawm kev txaus siab. Feem ntau, cov "channel" distors cov kis polarization, los yog ib tug los yog ob qho tib si kav hlau txais xov tsis nyob rau hauv ib tug ruaj khov kev taw qhia.
Kev xaiv ntawm polarization los siv feem ntau yog txiav txim siab los ntawm kev teeb tsa lossis huab cua. Piv txwv li, kab rov tav polarized kav hlau txais xov yuav ua tau zoo dua thiab tswj nws cov polarization thaum ntsia ze ntawm lub qab nthab; conversely, ib tug vertically polarized kav hlau txais xov yuav ua tau zoo dua thiab tswj nws cov polarization kev ua tau zoo thaum ntsia ze ntawm ib sab phab ntsa.
Cov kav hlau txais xov dipole dav siv (dawb lossis folded) yog kab rov tav polarized nyob rau hauv nws "ib txwm" mounting orientation (Daim duab 4) thiab feem ntau tig 90 degrees los xav txog ntsug polarization thaum xav tau lossis txhawb hom polarization nyiam (Daim duab 5).
Daim duab 4: Tus kav hlau txais xov dipole feem ntau yog mounted horizontally ntawm nws mast los muab kab rov tav polarization
Daim duab 5: Rau cov ntawv thov uas xav tau ntsug polarization, lub kav hlau txais xov dipole tuaj yeem txuas tau raws li qhov chaw kav hlau txais xov
Vertical polarization feem ntau yog siv rau cov xov tooj cua hauv xov tooj ntawm tes, xws li cov neeg siv los ntawm cov neeg teb thawj zaug, vim hais tias ntau lub xov tooj cua vertically polarized antenna designs kuj muab cov qauv hluav taws xob omnidirectional. Yog li ntawd, cov kav hlau txais xov zoo li no tsis tas yuav tsum tau reoriented txawm tias cov kev taw qhia ntawm lub xov tooj cua thiab kav hlau txais xov hloov.
3 - 30 MHz high zaus (HF) zaus kav hlau txais xov yog feem ntau tsim raws li cov xov hlau ntev yooj yim strung ua ke horizontally ntawm brackets. Nws qhov ntev yog txiav txim los ntawm lub wavelength (10 - 100 m). Hom kav hlau txais xov no yog horizontally polarized.
Nws yog ib qho tsim nyog sau cia tias xa mus rau qhov band no li "siab zaus" tau pib ntau xyoo dhau los, thaum 30 MHz yog qhov tseeb siab. Txawm hais tias qhov kev piav qhia tam sim no zoo li dhau los, nws yog ib qho kev xaiv los ntawm International Telecommunications Union thiab tseem siv dav.
Qhov kev xaiv polarization tuaj yeem txiav txim siab nyob rau hauv ob txoj kev: siv cov av nthwv dej kom muaj zog luv luv ntawm cov khoom siv tshaj tawm los ntawm kev siv 300 kHz - 3 MHz nruab nrab nthwv dej (MW) band, lossis siv lub ntuj nthwv dej kom ntev dua los ntawm ionosphere Txuas. Feem ntau hais lus, vertically polarized kav hlau txais xov muaj qhov zoo dua hauv av nthwv dej propagation, thaum kab rov tav polarized kav hlau txais xov muaj kev ua haujlwm zoo dua ntuj.
Lub voj voog polarization yog dav siv rau satellites vim hais tias lub satellite txoj kev taw qhia txog cov chaw nres tsheb hauv av thiab lwm cov satellites hloov tas li. Kev ua tau zoo ntawm kev xa tawm thiab txais cov kav hlau txais xov yog qhov zoo tshaj plaws thaum ob qho tib si yog voj voog polarized, tab sis cov kav hlau txais xov polarized linearly siv tau nrog CP kav hlau txais xov, txawm hais tias muaj qhov tsis zoo polarization.
Polarization kuj tseem ceeb rau 5G systems. Qee qhov 5G ntau qhov kev tawm tswv yim / ntau qhov tso tawm (MIMO) cov kav hlau txais xov arrays ua tiav kev nce ntxiv los ntawm kev siv polarization kom siv tau zoo dua qhov muaj spectrum. Qhov no yog ua tiav los ntawm kev sib xyaw ntawm cov teeb liab sib txawv polarizations thiab spatial multiplexing ntawm cov kav hlau txais xov (qhov chaw sib txawv).
Lub kaw lus tuaj yeem xa ob cov ntaub ntawv ntws vim tias cov ntaub ntawv ntws tau txuas nrog cov kav hlau txais xov orthogonally polarized thiab tuaj yeem rov qab los ntawm nws tus kheej. Txawm hais tias qee qhov kev sib txawv ntawm qhov sib txawv vim yog txoj hauv kev thiab kev tsis sib haum xeeb, kev xav, kev sib txuam, thiab lwm yam tsis zoo, tus txais tau siv cov txheej txheem sophisticated kom rov qab tau txhua qhov teeb meem qub, uas ua rau qis me ntsis yuam kev (BER) thiab thaum kawg txhim kho spectrum Siv.
nyob rau hauv xaus
Polarization yog ib qho tseem ceeb ntawm cov kav hlau txais xov uas feem ntau tsis saib xyuas. Linear (xws li kab rov tav thiab ntsug) polarization, oblique polarization, ncig polarization thiab elliptical polarization yog siv rau kev siv sib txawv. Qhov ntau ntawm qhov kawg-rau-kawg RF kev ua tau zoo ntawm tus kav hlau txais xov tuaj yeem ua tiav nyob ntawm nws qhov kev txheeb ze thiab kev sib haum xeeb. Cov kav hlau txais xov txheem muaj cov polarization sib txawv thiab tsim nyog rau qhov sib txawv ntawm cov spectrum, muab cov polarization nyiam rau lub hom phiaj daim ntawv thov.
Cov khoom pom zoo:
| RM-PAB 2030-15 | ||
| Tsis muaj | Hom | Chav tsev |
| Ntau zaus | 20-30 | GHz |
| Tau txais | 15 Typ. | dBi |
| VSWR | 1.3 Typ. | |
| Polarization | Dual Tawm | |
| Hla Pol. Muab cais nyob ib leeg | 60 Typ. | dB |
| Chaw nres nkoj Isolation | 70 Typ. | dB |
| Txuas | SMA-Female ua | |
| Khoom siv | Al | |
| Ua tiav | Xim | |
| Loj(L * W * H) | 83.9 * 39.6 * 69.4 hli±5) | mm |
| Qhov hnyav | 0.074 ib | kg |
| RM-SIB 118-10 | ||
| Yam khoom | Specification | Chav tsev |
| Ntau zaus | 1-18 | GHz |
| Tau txais | 10 Typ. | dBi |
| VSWR | 1.5 Typ. | |
| Polarization | Tawm | |
| Hla Po. Muab cais nyob ib leeg | 30 Typ. | dB |
| Txuas | SMA- Poj niam | |
| Ua tiav | Ptsis yog | |
| Khoom siv | Al | |
| Loj(L * W * H) | 182.4 * 185.1 * 116.6 hli±5) | mm |
| Qhov hnyav | 0.603 ib | kg |
| RM-CDPHA218-15 | ||
| Tsis muaj | Hom | Chav tsev |
| Ntau zaus | 2-18 | GHz |
| Tau txais | 15 Typ. | dBi |
| VSWR | 1.5 Typ. |
|
| Polarization | Dual Tawm |
|
| Hla Pol. Muab cais nyob ib leeg | 40 | dB |
| Chaw nres nkoj Isolation | 40 | dB |
| Txuas | SMA-F |
|
| Kev kho saum npoo | Ptsis yog |
|
| Loj(L * W * H) | 276 * 147 * 147 hli±5) | mm |
| Qhov hnyav | 0.945 ib | kg |
| Khoom siv | Al |
|
| Ua haujlwm kub | -40+85 | °C |
| RM-PIB 9395-22 | ||
| Tsis muaj | Hom | Chav tsev |
| Ntau zaus | 93-95 : kuv | GHz |
| Tau txais | 22 Typ. | dBi |
| VSWR | 1.3 Typ. |
|
| Polarization | Dual Tawm |
|
| Hla Pol. Muab cais nyob ib leeg | 60 Typ. | dB |
| Chaw nres nkoj Isolation | 67 Sib. | dB |
| Txuas | WR 10 |
|
| Khoom siv | Cu |
|
| Ua tiav | Golden |
|
| Loj(L * W * H) | 69.3 * 19.1 * 21.2 hli±5) | mm |
| Qhov hnyav | 0.015 ib | kg |
Lub sij hawm xa tuaj: Plaub Hlis-11-2024
