Kuchita bwino kwa mlongoti kumayenderana ndi mphamvu zomwe zimaperekedwa ku mlongoti ndi mphamvu yotulutsidwa ndi mlongoti.Mlongoti wothandiza kwambiri udzatulutsa mphamvu zambiri zoperekedwa ku mlongoti.Mlongoti wosagwira ntchito bwino umatenga mphamvu zambiri zomwe zatayika mkati mwa mlongoti.Mlongoti wosagwira ntchito ukhozanso kukhala ndi mphamvu zambiri zowonekera chifukwa cha kusagwirizana.Chepetsani mphamvu yowunikira ya mlongoti wosagwira bwino ntchito poyerekeza ndi mlongoti wogwira mtima kwambiri.
[Zolemba pambali: Kusokoneza kwa antenna kumakambidwa m'mutu wina.Kusagwirizana kwa Impedans kumawonetsedwa ndi mphamvu yochokera ku mlongoti chifukwa chopingasacho ndi mtengo wolakwika.Chifukwa chake, izi zimatchedwa impedance mismatch.]
Mtundu wa kutayika mkati mwa mlongoti ndi kutayika kwa conduction.Kutayika kwa conduction kumachitika chifukwa cha kukhathamiritsa kwa mlongoti.Njira ina yotayika ndikutayika kwa dielectric.Kutayika kwa dielectric mu mlongoti kumachitika chifukwa cha kayendedwe kazinthu za dielectric.Zida zotetezera zimatha kupezeka mkati kapena mozungulira mlongoti.
Chiŵerengero cha mphamvu ya mlongoti ku mphamvu yowunikira chikhoza kulembedwa ngati mphamvu yowonjezera ya mlongoti.Ichi ndi equation [1].Imadziwikanso kuti kugwiritsa ntchito bwino kwa mlongoti wa radiation.
[Chiwerengero patsamba 1]
Kuchita bwino ndi chiŵerengero.Chiŵerengerochi nthawi zonse chimakhala pakati pa 0 ndi 1. Kuchita bwino nthawi zambiri kumaperekedwa pamlingo waperesenti.Mwachitsanzo, mphamvu ya 0,5 ndi 50% yofanana.Kuchita bwino kwa mlongoti kumatchulidwanso nthawi zambiri mu ma decibel (dB).Kuchita bwino kwa 0.1 ndikofanana ndi 10%.Izi ndi zofanananso ndi -10 decibels (-10 decibels).Kuchita bwino kwa 0.5 ndikofanana ndi 50%.Izi ndizofanananso ndi -3 decibels (dB).
Equation yoyamba nthawi zina imatchedwa mphamvu ya radiation ya tinyanga.Izi zimasiyanitsa ndi mawu ena omwe amagwiritsidwa ntchito kwambiri omwe amatchedwa mphamvu yonse ya mlongoti.Kugwiritsa Ntchito Bwino Kwambiri kwa Antenna radiation kuchulukitsidwa ndi kutayika kosagwirizana kwa mlongoti.Kutayika kosagwirizana ndi Impedans kumachitika pamene mlongoti walumikizidwa ndi chingwe chotumizira kapena cholandila.Izi zitha kufotokozedwa mwachidule mu formula [2].
[Equation 2]
formula [2]
Kutayika kosagwirizana kwa mlongoti nthawi zonse kumakhala nambala pakati pa 0 ndi 1. Chifukwa chake, mphamvu zonse za mlongoti nthawi zonse zimakhala zochepa poyerekeza ndi mphamvu ya radiation.Kubwereza izi, ngati palibe zotayika, mphamvu ya radiation ndiyofanana ndi kuchuluka kwa mlongoti chifukwa cha kusagwirizana kwamphamvu.
Kuwongolera magwiridwe antchito ndi chimodzi mwazinthu zofunika kwambiri za antenna.Itha kukhala pafupi kwambiri ndi 100% yokhala ndi satellite dish, antenna yanyanga, kapena theka lawavelength dipole popanda zinthu zotayika mozungulira.Tinyanga zamafoni am'manja kapena tinyanga tamagetsi ogula nthawi zambiri zimakhala ndi 20% -70%.Izi ndi zofanana ndi -7 dB -1.5 dB (-7, -1.5 dB).Nthawi zambiri chifukwa cha kutayika kwamagetsi ndi zinthu zozungulira mlongoti.Izi zimakonda kuyamwa mphamvu zina zowunikira.Mphamvuyi imasandulika kukhala mphamvu ya kutentha ndipo palibe ma radiation.Izi zimachepetsa mphamvu ya mlongoti.Tinyanga tawayilesi zamagalimoto zimatha kugwira ntchito pamawayilesi a AM ndi mphamvu ya 0.01.[Iyi ndi 1% kapena -20 dB.] Kulephera kumeneku ndi chifukwa chakuti mlongoti ndi wocheperapo kuposa theka la kutalika kwa mafunde pamafupipafupi ogwiritsira ntchito.Izi zimachepetsa kwambiri mphamvu ya mlongoti.Maulalo opanda zingwe amasungidwa chifukwa nsanja zowulutsa za AM zimagwiritsa ntchito mphamvu zotumizira zambiri.
Kutayika kosagwirizana kwa Impedance kumakambidwa mu Smith Chart ndi Impedance Matching zigawo.Kufananiza kwa impedance kumatha kupititsa patsogolo magwiridwe antchito a mlongoti.
Kupeza kwa antenna
Kupeza kwa mlongoti kwa nthawi yayitali kumatanthawuza kuchuluka kwa mphamvu zomwe zimaperekedwa kumalo okwera kwambiri, poyerekeza ndi gwero la isotropic.Kupeza kwa mlongoti kumatchulidwa kawirikawiri papepala lachidziwitso cha mlongoti.Kupindula kwa mlongoti ndikofunikira chifukwa kumaganizira zotayika zenizeni zomwe zimachitika.
Mlongoti wokhala ndi phindu la 3 dB zikutanthauza kuti mphamvu yolandilidwa kuchokera ku mlongoti ndi 3 dB yokwera kwambiri kuposa momwe ingalandirire kuchokera ku mlongoti wa isotropic wosatayika womwe uli ndi mphamvu yolowetsamo yomweyo.3 dB ikufanana ndi kuwirikiza kawiri magetsi.
Kupindula kwa mlongoti nthawi zina kumakambidwa ngati ntchito yolowera kapena ngodya.Komabe, nambala imodzi ikatchula phindu, ndiye kuti nambalayo ndiye phindu lalikulu la mbali zonse."G" ya phindu la mlongoti akhoza kufananizidwa ndi chiwongolero cha "D" chamtundu wamtsogolo.
[Chiwerengero patsamba 3]
Kupindula kwa mlongoti weniweni, womwe ukhoza kukhala wokwera kwambiri ngati satellite dish, ndi 50 dB.Kuwongolera kumatha kukhala otsika ngati 1.76 dB ngati mlongoti weniweni (monga mlongoti wachidule wa dipole).Kuwongolera sikungakhale kochepera 0 dB.Komabe, phindu lalikulu la mlongoti likhoza kukhala laling'ono.Izi zimachitika chifukwa cha kutayika kapena kusachita bwino.Tinyanga tating'onoting'ono tamagetsi ndi tinyanga tating'onoting'ono tomwe timagwira ntchito pa utali wafupipafupi wa ma frequency omwe mlongotiyo umagwirira ntchito.Tinyanga zing'onozing'ono zimatha kukhala zopanda ntchito.Kupindula kwa mlongoti nthawi zambiri kumakhala pansi -10 dB, ngakhale kusagwirizana kwa impedance sikukuganiziridwa.
Nthawi yotumiza: Nov-16-2023
