Cov kws ua hluav taws xob paub tias cov antennas xa thiab txais cov cim hauv daim ntawv ntawm cov nthwv dej ntawm lub zog electromagnetic (EM) piav qhia los ntawm Maxwell cov qauv. Ib yam li ntau lub ncauj lus, cov qauv no, thiab kev nthuav dav, cov khoom ntawm electromagnetism, tuaj yeem kawm ntawm ntau qib, los ntawm cov nqe lus zoo sib xws mus rau cov qauv nyuaj.
Muaj ntau yam txog kev nthuav dav ntawm lub zog hluav taws xob, ib qho yog polarization, uas tuaj yeem muaj ntau qib ntawm kev cuam tshuam lossis kev txhawj xeeb hauv daim ntawv thov thiab lawv cov qauv tsim antenna. Cov hauv paus ntsiab lus ntawm polarization siv rau txhua qhov hluav taws xob hluav taws xob, suav nrog RF / wireless, lub zog kho qhov muag, thiab feem ntau siv rau hauv cov ntawv thov kho qhov muag.
Antenna polarization yog dab tsi?
Ua ntej nkag siab txog kev sib hloov ntawm lub zog (polarization), peb yuav tsum xub nkag siab txog cov ntsiab cai ntawm cov nthwv dej hluav taws xob. Cov nthwv dej no muaj cov teb hluav taws xob (E fields) thiab cov teb sib nqus (H fields) thiab txav mus rau ib qho kev taw qhia. Cov teb E thiab H yog perpendicular rau ib leeg thiab rau qhov kev taw qhia ntawm lub dav hlau nthwv dej.
Polarization yog hais txog lub dav hlau E-field los ntawm qhov pom ntawm lub teeb liab transmitter: rau kab rov tav polarization, lub teb hluav taws xob yuav txav mus rau sab hauv lub dav hlau kab rov tav, thaum rau ntsug polarization, lub teb hluav taws xob yuav oscillate nce thiab nqis hauv lub dav hlau ntsug. (Daim duab 1).
Daim Duab 1: Cov nthwv dej hluav taws xob electromagnetic muaj cov khoom sib txuas ua ke E thiab H
Kev sib hloov polarization thiab kev sib hloov polarization
Cov hom polarization muaj xws li cov hauv qab no:
Hauv kev sib txuas lus yooj yim linear polarization, ob qho kev sib txuas lus uas ua tau yog orthogonal (perpendicular) rau ib leeg (Daim Duab 2). Hauv kev xav, lub kav hlau txais xov polarized kab rov tav yuav tsis "pom" lub teeb liab los ntawm lub kav hlau txais xov polarized ntsug thiab rov qab los, txawm tias ob qho tib si ua haujlwm ntawm tib lub zaus. Qhov zoo dua lawv tau sib phim, qhov ntau lub teeb liab raug ntes, thiab kev hloov pauv zog yog qhov siab tshaj plaws thaum polarizations phim.
Daim Duab 2: Linear polarization muab ob txoj kev xaiv polarization ntawm cov ces kaum sab xis rau ib leeg
Lub polarization oblique ntawm lub antenna yog ib hom linear polarization. Ib yam li cov polarization kab rov tav thiab ntsug yooj yim, qhov polarization no tsuas yog ua rau muaj kev nkag siab hauv ib puag ncig hauv ntiaj teb. Oblique polarization yog nyob ntawm lub kaum sab xis ntawm ± 45 degrees rau lub dav hlau kab rov tav. Thaum qhov no tsuas yog lwm hom ntawm linear polarization, lo lus "linear" feem ntau tsuas yog hais txog cov antennas polarized kab rov tav lossis ntsug.
Txawm hais tias muaj qee qhov kev poob, cov cim xa (lossis tau txais) los ntawm lub kav hlau txais xov diagonal tsuas yog ua tau nrog cov kav hlau txais xov kab rov tav lossis ntsug. Cov kav hlau txais xov obliquely polarized muaj txiaj ntsig thaum lub polarization ntawm ib lossis ob lub kav hlau txais xov tsis paub lossis hloov pauv thaum siv.
Kev sib hloov polarization (CP) nyuaj dua li kev sib hloov linear. Hauv hom no, kev sib hloov polarization uas sawv cev los ntawm E field vector tig thaum lub teeb liab kis mus. Thaum tig mus rau sab xis (saib ntawm lub transmitter), kev sib hloov polarization hu ua kev sib hloov polarization sab xis (RHCP); thaum tig mus rau sab laug, kev sib hloov polarization sab laug (LHCP) (Daim Duab 3)
Daim Duab 3: Hauv kev sib hloov voj voog, E field vector ntawm nthwv dej electromagnetic tig; qhov kev tig no tuaj yeem yog sab xis lossis sab laug.
Ib lub teeb liab CP muaj ob lub nthwv dej orthogonal uas tsis nyob hauv theem. Yuav tsum muaj peb yam mob los tsim lub teeb liab CP. Lub teb E yuav tsum muaj ob lub khoom orthogonal; ob lub khoom yuav tsum yog 90 degrees tawm ntawm theem thiab sib npaug hauv qhov loj. Ib txoj hauv kev yooj yim los tsim CP yog siv lub kav hlau txais xov helical.
Elliptical polarization (EP) yog ib hom CP. Cov nthwv dej elliptically polarized yog qhov nce uas tsim los ntawm ob lub nthwv dej linearly polarized, zoo li cov nthwv dej CP. Thaum ob lub nthwv dej linearly polarized uas muaj qhov sib npaug sib luag ua ke, ib lub nthwv dej elliptically polarized raug tsim tawm.
Qhov kev tsis sib xws ntawm polarization ntawm cov antennas yog piav qhia los ntawm qhov polarization loss factor (PLF). Cov parameter no yog qhia hauv decibels (dB) thiab yog ib qho kev ua haujlwm ntawm qhov sib txawv ntawm lub kaum sab xis polarization ntawm cov antennas xa thiab txais. Hauv kev xav, PLF tuaj yeem ntau ntawm 0 dB (tsis muaj kev poob) rau lub antenna uas sib dhos zoo meej mus rau infinite dB (infinite loss) rau lub antenna orthogonal zoo meej.
Qhov tseeb, txawm li cas los xij, qhov kev sib phim (lossis kev tsis sib haum) ntawm polarization tsis zoo tag nrho vim tias qhov chaw kho tshuab ntawm lub antenna, tus cwj pwm ntawm tus neeg siv, kev cuam tshuam ntawm channel, kev cuam tshuam ntau txoj kev, thiab lwm yam xwm txheej tuaj yeem ua rau muaj qee qhov kev cuam tshuam ntawm lub zog hluav taws xob xa mus. Thaum pib, yuav muaj 10 - 30 dB lossis ntau dua ntawm cov teeb liab hla-polarization "leakage" los ntawm orthogonal polarization, uas qee zaum yuav txaus los cuam tshuam nrog kev rov qab los ntawm cov teeb liab xav tau.
Qhov sib txawv, qhov tseeb PLF rau ob lub antennas sib phim nrog lub polarization zoo tagnrho yuav yog 10 dB, 20 dB, lossis ntau dua, nyob ntawm qhov xwm txheej, thiab tej zaum yuav cuam tshuam kev rov qab los ntawm lub teeb liab. Hauv lwm lo lus, kev hla polarization tsis xav tau thiab PLF tuaj yeem ua haujlwm ob txoj kev los ntawm kev cuam tshuam nrog lub teeb liab xav tau lossis txo lub zog teeb liab xav tau.
Vim li cas ho xav txog polarization?
Kev ua polarization ua haujlwm ua ob txoj kev: ob lub antennas sib phim ntau dua thiab muaj tib lub polarization, lub zog ntawm lub teeb liab tau txais zoo dua. Ntawm qhov tod tes, kev sib phim polarization tsis zoo ua rau nws nyuaj rau cov neeg txais, txawm tias npaj siab lossis tsis txaus siab, kom ntes tau txaus ntawm lub teeb liab uas xav tau. Hauv ntau qhov xwm txheej, "channel" ua rau lub polarization xa mus tsis sib xws, lossis ib lossis ob lub antennas tsis nyob hauv qhov kev taw qhia ruaj khov.
Qhov kev xaiv ntawm kev siv polarization twg feem ntau yog txiav txim siab los ntawm kev teeb tsa lossis huab cua. Piv txwv li, lub kav hlau txais xov polarized kab rov tav yuav ua haujlwm zoo dua thiab tswj nws qhov polarization thaum teeb tsa ze ntawm lub qab nthab; ntawm qhov tod tes, lub kav hlau txais xov polarized ntsug yuav ua haujlwm zoo dua thiab tswj nws qhov kev ua polarization thaum teeb tsa ze ntawm phab ntsa sab.
Lub kav hlau txais xov dipole uas siv dav dav (dawb lossis tais) yog polarized kab rov tav hauv nws qhov "ib txwm" mounting orientation (Daim Duab 4) thiab feem ntau tig 90 degrees los xav tias polarization ntsug thaum xav tau lossis txhawb nqa hom polarization nyiam (Daim Duab 5).
Daim Duab 4: Lub kav hlau txais xov dipole feem ntau yog mounted kab rov tav ntawm nws lub mast los muab kab rov tav polarization
Daim Duab 5: Rau cov ntawv thov uas xav tau kev sib hloov ntsug, lub kav hlau txais xov dipole tuaj yeem ntsia tau raws li qhov chaw uas lub kav hlau txais xov ntes tau
Kev siv polarization ntsug feem ntau yog siv rau cov xov tooj cua txawb tes, xws li cov uas siv los ntawm cov neeg teb thawj zaug, vim tias ntau lub kav hlau txais xov tooj cua polarized ntsug kuj muab cov qauv hluav taws xob omnidirectional. Yog li ntawd, cov kav hlau txais xov tooj cua no tsis tas yuav tsum tau hloov pauv txawm tias qhov kev taw qhia ntawm lub xov tooj cua thiab kav hlau txais xov tooj hloov pauv.
Cov kav hlau txais xov tooj cua zaus siab (HF) 3 - 30 MHz feem ntau yog tsim los ua cov xov hlau ntev yooj yim khi ua ke kab rov tav ntawm cov brackets. Nws qhov ntev yog txiav txim siab los ntawm qhov ntev ntawm lub teeb (10 - 100 m). Hom kav hlau txais xov tooj cua no yog polarized kab rov tav.
Nws tsim nyog sau tseg tias kev hais txog qhov band no ua "high frequency" pib ntau xyoo dhau los, thaum 30 MHz yog high frequency. Txawm hais tias cov lus piav qhia no zoo li qub lawm, nws yog lub npe raug cai los ntawm International Telecommunications Union thiab tseem siv dav.
Qhov kev sib hloov polarization uas nyiam yuav raug txiav txim siab ua ob txoj kev: siv cov nthwv dej hauv av rau kev tshaj tawm luv luv los ntawm cov khoom siv tshaj tawm siv 300 kHz - 3 MHz nruab nrab nthwv dej (MW) band, lossis siv nthwv dej saum ntuj rau qhov deb ntev dua los ntawm ionosphere Link. Feem ntau hais lus, cov kav hlau txais xov polarized ntsug muaj kev nthuav dav nthwv dej hauv av zoo dua, thaum cov kav hlau txais xov polarized kab rov tav muaj kev ua tau zoo dua ntawm nthwv dej saum ntuj.
Kev siv polarization ncig yog siv dav rau cov satellites vim tias qhov kev taw qhia ntawm lub satellite piv rau cov chaw nres tsheb hauv av thiab lwm lub satellites hloov pauv tas li. Kev ua haujlwm zoo ntawm cov antennas xa thiab txais yog qhov zoo tshaj plaws thaum ob qho tib si yog polarized ncig, tab sis linearly polarized antennas tuaj yeem siv nrog CP antennas, txawm hais tias muaj qhov poob polarization.
Kev sib cais kuj tseem ceeb rau 5G systems. Qee qhov 5G multiple-input/multiple-output (MIMO) antenna arrays ua tiav kev nce ntxiv los ntawm kev siv polarization kom siv tau zoo dua cov spectrum muaj. Qhov no ua tiav los ntawm kev siv kev sib xyaw ua ke ntawm ntau yam teeb liab polarizations thiab spatial multiplexing ntawm cov antennas (qhov chaw sib txawv).
Lub kaw lus tuaj yeem xa ob txoj kev xa ntaub ntawv vim tias cov ntaub ntawv txuas nrog los ntawm cov kav hlau txais xov orthogonally polarized ywj pheej thiab tuaj yeem rov qab tau ywj pheej. Txawm tias muaj qee qhov kev hla-polarization vim yog txoj kev thiab kev cuam tshuam ntawm channel, kev cuam tshuam, ntau txoj kev, thiab lwm yam tsis zoo, lub receiver siv cov algorithms zoo heev los rov qab txhua lub teeb liab qub, ua rau muaj qhov yuam kev tsawg (BER) thiab thaum kawg txhim kho kev siv spectrum.
xaus lus
Kev sib hloov polarization yog ib qho tseem ceeb ntawm lub kav hlau txais xov uas feem ntau raug saib tsis taus. Kev sib hloov linear (suav nrog kab rov tav thiab ntsug) polarization, oblique polarization, circular polarization thiab elliptical polarization yog siv rau ntau yam kev siv. Qhov ntau ntawm qhov kawg-rau-kawg RF kev ua tau zoo uas lub kav hlau txais xov tuaj yeem ua tiav nyob ntawm nws qhov kev taw qhia thiab kev sib dhos. Cov kav hlau txais xov txheem muaj cov polarizations sib txawv thiab tsim nyog rau ntau qhov ntawm cov spectrum, muab cov polarization nyiam rau lub hom phiaj daim ntawv thov.
Cov Khoom Pom Zoo:
| RM-DPHA2030-15 | ||
| Cov Kev Cai | Ib txwm muaj | Chav |
| Zaus Ntau | 20-30 | GHz |
| Tau Txais | 15 Hom. | dBi |
| VSWR | 1.3 Hom. | |
| Kev sib hloov pauv | Ob Chav Kab ncaj | |
| Kev Cais Tawm Ntawm Tus Neeg Mob | 60 Hom. | dB |
| Kev Cais Chaw Nres Nkoj | 70 Hom. | dB |
| Tus Txuas | SMA-Femail | |
| Khoom siv | Al | |
| Kev Ua Tiav | Xim | |
| Loj(L * W * H) | 83.9 * 39.6 * 69.4 (±5) | mm |
| Qhov hnyav | 0.074 | kg |
| RM-BDHA118-10 | ||
| Khoom | Cov Lus Qhia Tshwj Xeeb | Chav tsev |
| Zaus Ntau | 1-18 | GHz |
| Tau Txais | 10 Hom. | dBi |
| VSWR | 1.5 Hom. | |
| Kev sib hloov pauv | Kab ncaj | |
| Kev Cais Tawm Ntawm Cross Po | 30 Hom. | dB |
| Tus Txuas | SMA-Poj Niam | |
| Kev Ua Tiav | Ptsis yog | |
| Khoom siv | Al | |
| Loj(L * W * H) | 182.4 * 185.1 * 116.6 (±5) | mm |
| Qhov hnyav | 0.603 | kg |
| RM-CDPHA218-15 | ||
| Cov Kev Cai | Ib txwm muaj | Chav |
| Zaus Ntau | 2-18 | GHz |
| Tau Txais | 15 Hom. | dBi |
| VSWR | 1.5 Hom. |
|
| Kev sib hloov pauv | Ob Chav Kab ncaj |
|
| Kev Cais Tawm Ntawm Tus Neeg Mob | 40 | dB |
| Kev Cais Chaw Nres Nkoj | 40 | dB |
| Tus Txuas | SMA-F |
|
| Kev Kho Mob Nto | Ptsis yog |
|
| Loj(L * W * H) | 276 * 147 * 147 (±5) | mm |
| Qhov hnyav | 0.945 | kg |
| Khoom siv | Al |
|
| Kub Ua Haujlwm | -40-+85 | °C |
| RM-BDPHA9395-22 | ||
| Cov Kev Cai | Ib txwm muaj | Chav |
| Zaus Ntau | 93-95 | GHz |
| Tau Txais | 22 Hom. | dBi |
| VSWR | 1.3 Hom. |
|
| Kev sib hloov pauv | Ob Chav Kab ncaj |
|
| Kev Cais Tawm Ntawm Tus Neeg Mob | 60 Hom. | dB |
| Kev Cais Chaw Nres Nkoj | 67 Hom. | dB |
| Tus Txuas | WR10 |
|
| Khoom siv | Cu |
|
| Kev Ua Tiav | Kub |
|
| Loj(L * W * H) | 69.3 * 19.1 * 21.2 (±5) | mm |
| Qhov hnyav | 0.015 | kg |
Lub sijhawm tshaj tawm: Plaub Hlis-11-2024
