Kugwira ntchito bwino kwa antenna kumagwirizana ndi mphamvu yomwe imaperekedwa ku antenna ndi mphamvu yomwe imaperekedwa ndi antenna. Antena yogwira ntchito bwino kwambiri idzatulutsa mphamvu zambiri zomwe zimaperekedwa ku antenna. Antena yosagwira ntchito imayamwa mphamvu zambiri zomwe zimatayika mkati mwa antenna. Antena yosagwira ntchito ingakhalenso ndi mphamvu zambiri zomwe zimawonetsedwa chifukwa cha kusagwirizana kwa impedance. Kuchepetsa mphamvu yotulutsidwa ya antenna yosagwira ntchito poyerekeza ndi antenna yogwira ntchito bwino.
[Chidziwitso cham'mbali: Kusagwirizana kwa ma antenna kukufotokozedwa m'mutu wotsatira. Kusagwirizana kwa ma antenna ndi mphamvu yowonetsedwa kuchokera ku antenna chifukwa kusagwirizana ndi mtengo wolakwika. Chifukwa chake, izi zimatchedwa kusagwirizana kwa ma antenna. ]
Mtundu wa kutayika mkati mwa antenna ndi kutayika kwa conduction. Kutayika kwa conduction kumachitika chifukwa cha conductivity yochepa ya antenna. Njira ina yotayika ndi kutayika kwa dielectric. Kutayika kwa dielectric mu antenna kumachitika chifukwa cha conductivity mu dielectric. Zinthu zotetezera zitha kukhala mkati kapena mozungulira antenna.
Chiŵerengero cha mphamvu ya antenna ku mphamvu yowala chingalembedwe ngati mphamvu yolowera ya antenna. Ichi ndi equation [1]. Imadziwikanso kuti mphamvu ya antenna yowala.
[Chiyerekezo 1]
Kuchita bwino ndi chiŵerengero. Chiŵerengerochi nthawi zonse chimakhala pakati pa 0 ndi 1. Kuchita bwino nthawi zambiri kumaperekedwa pa peresenti. Mwachitsanzo, kuchita bwino kwa 0.5 kumakhala kofanana ndi 50%. Kuchita bwino kwa ma antenna nthawi zambiri kumatchulidwanso mu ma decibel (dB). Kuchita bwino kwa 0.1 ndikofanana ndi 10%. Izi ndizofanana ndi -10 decibel (-10 decibels). Kuchita bwino kwa 0.5 ndikofanana ndi 50%. Izi ndizofanananso ndi -3 decibels (dB).
Chiyerekezo choyamba nthawi zina chimatchedwa mphamvu ya radiation ya antenna. Izi zimasiyanitsa ndi mawu ena omwe amagwiritsidwa ntchito kwambiri otchedwa mphamvu yonse ya antenna. Kugwira Ntchito Konse Kogwira Ntchito Mphamvu ya radiation ya antenna imachulukitsidwa ndi kutayika kwa impedance mismatch kwa antenna. Kutayika kwa impedance mismatch kumachitika pamene antenna yalumikizidwa ndi chingwe chotumizira kapena cholandirira. Izi zitha kufotokozedwa mwachidule mu fomula [2].
[Chiyerekezo 2]
fomula [2]
Kutayika kwa kusagwirizana kwa Impedance nthawi zonse kumakhala pakati pa 0 ndi 1. Chifukwa chake, mphamvu yonse ya antenna nthawi zonse imakhala yocheperako kuposa mphamvu ya radiation. Kuti tibwerezenso izi, ngati palibe kutayika, mphamvu ya radiation ndi yofanana ndi mphamvu yonse ya antenna chifukwa cha kusagwirizana kwa impedance.
Kukonza magwiridwe antchito ndi chimodzi mwa zinthu zofunika kwambiri pa antenna. Ikhoza kukhala pafupi kwambiri ndi 100% ndi satellite dish, horn antenna, kapena half wavelength dipole popanda zinthu zotayika zozungulira. Ma antenna a foni yam'manja kapena ma antenna amagetsi nthawi zambiri amakhala ndi mphamvu ya 20%-70%. Izi ndizofanana ndi -7 dB -1.5 dB (-7, -1.5 dB). Nthawi zambiri chifukwa cha kutayika kwa zamagetsi ndi zinthu zozungulira antenna. Izi zimakonda kuyamwa mphamvu zina zowala. Mphamvuyo imasinthidwa kukhala mphamvu yotentha ndipo palibe kuwala. Izi zimachepetsa mphamvu ya antenna. Ma antenna a wailesi yamagalimoto amatha kugwira ntchito pa ma frequency a wailesi a AM okhala ndi mphamvu ya antenna ya 0.01. [Iyi ndi 1% kapena -20 dB.] Kulephera kugwira ntchito kumeneku kumachitika chifukwa antenna ndi yaying'ono kuposa theka la kutalika kwa nthawi yogwirira ntchito. Izi zimachepetsa kwambiri mphamvu ya antenna. Maulalo opanda zingwe amasungidwa chifukwa nsanja zowulutsa za AM zimagwiritsa ntchito mphamvu yotumizira kwambiri.
Kutayika kwa kusagwirizana kwa Impedance kumakambidwa mu gawo la Smith Chart ndi Impedance Matching. Kufananiza Impedance kungathandize kwambiri kuti antenna igwire bwino ntchito.
Kuchuluka kwa ma antenna
Kupeza ma antenna kwa nthawi yayitali kumafotokoza kuchuluka kwa mphamvu zomwe zimafalikira munjira ya peak radiation, poyerekeza ndi gwero la isotropic. Kupeza ma antenna kumatchulidwa kwambiri mu pepala lofotokozera la antenna. Kupeza ma antenna ndikofunikira chifukwa kumaganizira kutayika kwenikweni komwe kumachitika.
Antena yokhala ndi 3 dB gain imatanthauza kuti mphamvu yolandiridwa kuchokera ku antena ndi 3 dB yokwera kwambiri kuposa momwe ingalandirire kuchokera ku antena yopanda kutayika ya isotropic yokhala ndi mphamvu yolowera yomweyo. 3 dB ndi yofanana ndi kawiri mphamvu yamagetsi.
Kupeza ma antenna nthawi zina kumakambidwa ngati njira yolunjika kapena ngodya. Komabe, nambala imodzi ikatchula phindu, ndiye kuti nambalayo ndi phindu lalikulu la mbali zonse. "G" ya kupeza ma antenna ingayerekezeredwe ndi njira yolunjika ya "D" yamtundu wamtsogolo.
[Chiyerekezo 3]
Kuchuluka kwa antenna yeniyeni, komwe kungakhale kokwera ngati satellite dish yayikulu kwambiri, ndi 50 dB. Kuwongolera kumatha kukhala kotsika mpaka 1.76 dB ngati antenna yeniyeni (monga antenna ya dipole yayifupi). Kuwongolera sikungakhale kochepera 0 dB. Komabe, kuchuluka kwa antenna kumatha kukhala kochepa mwachisawawa. Izi zimachitika chifukwa cha kutayika kapena kusagwira ntchito bwino. Ma antenna ang'onoang'ono amagetsi ndi ma antenna ang'onoang'ono omwe amagwira ntchito pamlingo wa mafunde a pafupipafupi yomwe antenna imagwira ntchito. Ma antenna ang'onoang'ono amatha kukhala osagwira ntchito bwino. Kuchuluka kwa ma antenna nthawi zambiri kumakhala pansi pa -10 dB, ngakhale pamene kusagwirizana kwa impedance sikuganiziridwa.
Nthawi yotumizira: Novembala-16-2023
