Directivity ndi gawo lofunikira la antenna.Umu ndi muyeso wa momwe ma radiation a antenna olowera alili.Mlongoti umene umatulutsa mofanana kumbali zonse udzakhala ndi chiwongolero chofanana ndi 1. (Izi ndizofanana ndi ziro decibels -0 dB).
Ntchito ya ma spherical coordinates imatha kulembedwa ngati mawonekedwe a radiation:
[Chiwerengero patsamba 1]
Ma radiation okhazikika amakhala ndi mawonekedwe ofanana ndi mawonekedwe oyambira a radiation.Ma radiation odziwika bwino amachepetsedwa ndi kukula kotero kuti mtengo wapamwamba wa ma radiation umakhala wofanana ndi 1. (Yaikulu kwambiri ndi equation [1] ya "F").Mwamasamu, chilinganizo chowongolera (mtundu "D") chimalembedwa motere:
Izi zitha kuwoneka ngati zovuta zowongolera.Komabe, ma radiation a mamolekyu ndi ofunika kwambiri.Denominator imayimira mphamvu yapakati yowunikira mbali zonse.The equation ndiye muyeso wa nsonga yotulutsa mphamvu yogawidwa ndi avareji.Izi zimapereka chiwongolero cha mlongoti.
Directional paradigm
Mwachitsanzo, taganizirani ma equation awiri otsatirawa a mawonekedwe a radiation a tinyanga tiwiri.
Antenna 1
Antenna 2
Ma radiation awa amapangidwa mu Chithunzi 1. Chonde dziwani kuti mawonekedwe a radiation ndi ntchito ya polar angle theta (θ) Njira ya radiation si ntchito ya azimuth.(Mchitidwe wa radiation wa azimuthal sunasinthe).Kapangidwe ka radiation ka mlongoti woyamba ndi wocheperako, kenako mawonekedwe a radiation ya mlongoti wachiwiri.Chifukwa chake, tikuyembekeza kuti chiwongolerocho chikhale chotsika kwa mlongoti woyamba.
chithunzi 1. Chithunzi cha ma radiation cha mlongoti.Ali ndi mayendedwe apamwamba?
Pogwiritsa ntchito formula [1], titha kuwerengera kuti mlongoti uli ndi chiwongolero chapamwamba.Kuti muwone kumvetsetsa kwanu, ganizirani za Chithunzi 1 ndi momwe mungayendere.Kenako dziwani kuti ndi mlongoti uti womwe uli ndi chiwongolero chapamwamba osagwiritsa ntchito masamu.
Zotsatira zowerengera molunjika, gwiritsani ntchito formula [1]:
Kuwerengera kwa mlongoti 1, 1.273 (1.05 dB).
Kuwerengera kwa mlongoti 2 wolunjika, 2.707 (4.32 dB).
Kuchulukitsidwa kolunjika kumatanthauza mlongoti wolunjika kwambiri kapena wolunjika.Izi zikutanthauza kuti mlongoti wolandira 2 uli ndi mphamvu zokwana 2.707 kuwirikiza nsonga yake kuposa mlongoti wa omnidirectional.Mlongoti 1 udzapeza nthawi 1.273 mphamvu ya mlongoti wa omnidirectional.Tinyanga za Omnidirectional zimagwiritsidwa ntchito ngati zofotokozera wamba ngakhale palibe tinyanga ta isotropic.
Tinyanga zam'manja zimayenera kukhala ndi chiwongolero chochepa chifukwa ma siginecha amatha kuchokera mbali iliyonse.Mosiyana ndi izi, mbale za satellite zimakhala ndi chiwongolero chachikulu.Satellite dish imalandira zidziwitso kuchokera komwe kuli kokhazikika.Mwachitsanzo, ngati mutapeza mbale ya satellite ya TV, kampaniyo idzakuuzani komwe mungakuloze ndipo mbaleyo idzalandira chizindikiro chomwe mukufuna.
Titha ndi mndandanda wa mitundu ya tinyanga ndi kuwongolera kwawo.Izi zidzakupatsani lingaliro la momwe kuwongolera kuli kofala.
Mtundu wa mlongoti Mayendetsedwe apanthawi yake [decibel] (dB)
Mlongoti wachidule wa dipole 1.5 1.76
Theka-wave dipole antenna 1.64 2.15
Chigamba (microstrip antenna) 3.2-6.3 5-8
Nyanga ya nyanga 10-100 10-20
Mlongoti wa mbale 10-10,000 10-40
Monga momwe zomwe zili pamwambapa zikuwonetsa kuwongolera kwa mlongoti kumasiyana kwambiri.Chifukwa chake, ndikofunikira kumvetsetsa kuwongolera posankha mlongoti wabwino kwambiri wa pulogalamu yanu.Ngati mukufuna kutumiza kapena kulandira mphamvu kuchokera kunjira zingapo mbali imodzi ndiye kuti muyenera kupanga mlongoti wolunjika pang'ono.Zitsanzo za mapulogalamu a tinyanga zotsika kwambiri ndi monga mawailesi amgalimoto, mafoni am'manja, ndi intaneti opanda zingwe zamakompyuta.Kumbali inayi, ngati mukuchita zowonera patali kapena kusamutsa magetsi komwe mukufuna, ndiye kuti mlongoti wolunjika kwambiri udzafunika.Ma antenna olunjika kwambiri adzakulitsa kusamutsa mphamvu kuchokera komwe akufunidwa ndikuchepetsa ma siginecha kuchokera kumayendedwe osayenera.
Tiyerekeze kuti tikufuna mlongoti otsika.Kodi timachita bwanji izi?
Lamulo lalikulu la chiphunzitso cha mlongoti ndikuti mumafunika tinyanga tating'ono tamagetsi kuti tipangitse kuwongolera kochepa.Ndiye kuti, ngati mugwiritsa ntchito mlongoti wokhala ndi kukula kwa 0,25 - 0.5 wavelength, ndiye kuti muchepetse kuwongolera.Ma antennas a theka-wave dipole kapena theka-wavelength slot antennas nthawi zambiri amakhala ndi zowongolera zosakwana 3 dB.Izi ndizotsika monga momwe mungayendetsere.
Pamapeto pake, sitingapangitse tinyanga tating'onoting'ono kuposa kotala la kutalika kwa mawonekedwe popanda kuchepetsa mphamvu ya mlongoti ndi bandwidth ya mlongoti.Kuchita bwino kwa mlongoti ndi bandwidth ya antenna zidzakambidwa m'mitu yamtsogolo.
Kwa tinyanga tokhala ndi chiwongolero chachikulu, tidzafunika tinyanga tating'onoting'ono tambiri.Monga ma satellite dish antennas ndi ma nyanga antennas ali ndi chiwongolero chachikulu.Izi zili choncho chifukwa ndi zazitali zambiri za mafunde.
ndichoncho chifukwa chiyani?Pamapeto pake, chifukwa chake chikugwirizana ndi mawonekedwe a Fourier transform.Mukatenga kusintha kwa Fourier kwa kugunda kwakufupi, mumapeza mawonekedwe otakata.Fanizoli silikupezeka pozindikira mawonekedwe a radiation ya tinyanga.Mtundu wa radiation ukhoza kuganiziridwa ngati kusintha kwa Fourier kwa kagawidwe ka magetsi kapena magetsi motsatira mlongoti.Chifukwa chake, tinyanga tating'onoting'ono timakhala ndi ma radiation otakata (komanso otsika).Tinyanga zokhala ndi voteji yayikulu yofananira kapena kugawa kwapano Njira zowongolera kwambiri (ndikuwongolera kwambiri).
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Nthawi yotumiza: Nov-07-2023
