1.Iyini i-Antenna?
Njengoba sonke sazi, kukhona zonke izinhlobo ze-wimishini yokuxhumana engenamsebenziezimpilweni zethu, njenge-drone video downlink,isixhumanisi esingenantambo serobhothi, uhlelo lwe-digital meshfuthi lezi zinhlelo zokudlulisa umsakazo zisebenzisa amaza omsakazo ukudlulisa ulwazi olungenantambo njengevidiyo, izwi nedatha.Uthi luyisisetshenziswa esisetshenziselwa ukukhanyisa nokwamukela amaza omsakazo.
2.Umkhawulokudonsa wezinti
Lapho i-frequency yokusebenza ye-antenna ishintsha, izinga lokushintsha kwemingcele kagesi efanelekile yothingo ingaphakathi kwebanga elivumelekile.Ibanga lefrikhwensi elivumelekile ngalesi sikhathi ububanzi bebhendi ye-antenna, ngokuvamile ebizwa ngokuthi i-bandwidth.Noma iyiphi ithikithi inomkhawulokudonsa othile wokusebenza, futhi ayinawo umphumela ohambelanayo ngaphandle kwale bhendi yefrikhwensi.
Umkhawulokudonsa ophelele: ABW=fmax - fmin
Umkhawulokudonsa ohlobene: FBW=(fmax - fmin)/f0×100%
f0=1/2(fmax + fmin) imvamisa emaphakathi
Lapho i-antenna isebenza kumaza amaphakathi, isilinganiso segagasi lokuma sincane kakhulu futhi ukusebenza kahle kuphezulu kakhulu.
Ngakho-ke, ifomula yomkhawulokudonsa ohlobene imvamisa ichazwa kanje: FBW=2(fmax- fmin)/(fmax+ fmin)
Ngenxa yokuthi umkhawulokudonsa we-antenna uwububanzi befrikhwensi yokusebenza lapho ipharamitha eyodwa noma ezinye zezinto zikagesi zothiyo zihlangabezana nezidingo, imingcele ehlukene kagesi ingasetshenziswa ukukala ububanzi bebhendi yefrikhwensi.Isibonelo, ububanzi bebhendi ye-frequency ehambisana nobubanzi be-lobe engu-3dB (ububanzi be-lobe bubhekisela engeli phakathi kwamaphoyinti amabili lapho amandla emisebe ehla ngo-3dB, okungukuthi, ukuminyana kwamandla kuncipha ngesigamu, nhlangothi zombili zokuqondisa okukhulu kwemisebe. yelobe eyinhloko), kanye nobubanzi bebhendi yefrikhwensi lapho isilinganiso samagagasi esimile sihlangabezana nezidingo ezithile.Phakathi kwazo, okuvame ukusetshenziswa kakhulu yi-bandwidth elinganiswa ne-standing wave ratio.
3.Ubudlelwano phakathi kwefrikhwensi yokusebenza nosayizi we-antenna
Ngendlela efanayo, ijubane lokusabalalisa lamaza kagesi liqinisekile (lilingana nejubane lokukhanya endaweni engenalutho, eqoshwe ngokuthi c≈3×108m/s).Ngokusho kuka-c=λf, kungabonwa ukuthi ubude begagasi buhambisana ngokuphambene nemvamisa, futhi okubili kuwukuphela kobudlelwano obuhambisanayo.
Ubude be-antenna bulingana ngokuqondile nobude begagasi futhi buhambisana ngokuphambene nemvamisa.Okusho ukuthi, uma i-frequency iphezulu, ubude begagasi bufushane, futhi i-antenna ingenziwa ibe mfushane.Vele, ubude be-antenna ngokuvamile abulingani nobude beza obubodwa, kodwa ngokuvamile bungu-1/4 wamaza noma u-1/2 wamaza (ngokuvamile kusetshenziswa i-wavelength ehambisana nemvamisa yokusebenza emaphakathi).Ngoba uma ubude bekhondatha buyinani eliphelele lokuphindaphinda kwe-wavelength engu-1/4, umqhubi ubonisa izici zokukhala ngemvamisa yalolo bude obungamaza.Uma ubude be-conductor buyi-1/4 wavelength, inezici ze-resonance yochungechunge, futhi uma ubude be-conductor buyi-1/2 wavelength, inezici ze-resonance ezihambisanayo.Kulesi simo se-resonance, i-antenna ikhanya kakhulu futhi ukusebenza kahle kokudlulisela nokwamukela kuphezulu.Nakuba imisebe ye-oscillator idlula i-1/2 ye-wavelength, imisebe izoqhubeka ithuthukiswa, kodwa imisebe ephikisana nesigaba sengxenye eyeqile izoveza umphumela wokukhansela, ngakho-ke umphumela wemisebe jikelele usengozini.Ngakho-ke, izimpondo ezivamile zisebenzisa iyunithi yobude be-oscillator engu-1/4 wavelength noma 1/2 wavelength.Phakathi kwazo, i-antenna engu-1/4-wavelength ikakhulukazi isebenzisa umhlaba njengesibuko esikhundleni se-antenna ye-half-wave.
I-antenna engu-1/4 ye-wavelength ingafinyelela isilinganiso esifanele sokuma kwegagasi nomphumela wokusetshenziswa ngokulungisa uhlu, futhi ngesikhathi esifanayo, ingasindisa isikhala sokufaka.Kodwa-ke, ama-antenna alobu bude ngokuvamile anenzuzo ephansi futhi awakwazi ukuhlangabezana nezidingo zezimo ezithile zokudlulisela inzuzo ephezulu.Kulokhu, ama-antenna angu-1/2-wavelength ngokuvamile asetshenziswa.
Ukwengeza, kufakazelwe ngokombono nokusebenzayo ukuthi uhlu lwamaza wamaza angu-5/8 (lobu bude busondele ku-1/2 wavelength kodwa lunomsakazo onamandla kuno-1/2 wamaza wamaza) noma uhlu lokufinyeza lwamaza wamaza angu-5/8 (kukhona ikhoyili elayishayo engxenyeni yobude bebanga ukusuka phezulu kothi) ingaklanywa noma ikhethwe ukuze kutholwe ithikithi elingabizi kakhulu futhi lenze inzuzo ephezulu.
Kungabonakala ukuthi uma sazi imvamisa yokusebenza kwe-antenna, singabala ubude beza obuhambisanayo, bese sihlanganiswa nethiyori yomugqa wokudlulisa, izimo zesikhala sokufakwa kanye nezidingo zokuzuza kokudlulisela, singakwazi cishe ukwazi ubude obufanele bothi oludingekayo. .
Isikhathi sokuthumela: Oct-13-2023
