1. Menene Antenna?
Kamar yadda muka sani, akwai nau'ikan wna'urorin sadarwa mara amfania cikin rayuwarmu, kamar saukar da bidiyon drone,hanyar sadarwa mara waya ta robot, dijital raga tsarinkuma waɗannan tsarin watsa rediyo suna amfani da igiyoyin rediyo don watsa bayanai mara waya kamar bidiyo, murya da bayanai.Eriya ita ce na'urar da ake amfani da ita don haskakawa da karɓar raƙuman rediyo.
2.Antenna bandwidth
Lokacin da mitar aiki na eriya ta canza, matakin canjin ma'aunin lantarki masu dacewa na eriya yana cikin kewayon da aka yarda.Matsakaicin mitar da aka yarda a wannan lokacin shine nisa ɗin mitar eriya, yawanci ana kiranta da bandwidth.Kowace eriya tana da ƙayyadaddun bandwidth mai aiki, kuma ba shi da wani tasiri mai dacewa a wajen wannan rukunin mitar.
Cikakken bandwidth: ABW=fmax - fmin
Dangantakar bandwidth: FBW=(fmax - fmin)/f0×100%
f0=1/2(fmax + fmin) shine mitar cibiyar
Lokacin da eriya ke aiki a tsakiyar mitar, madaidaicin igiyar igiyar ruwa ita ce mafi ƙanƙanta kuma inganci shine mafi girma.
Saboda haka, ana bayyana ma'anar bandwidth dangi yawanci kamar: FBW=2(fmax-fmin)/(fmax+ fmin)
Saboda bandwidth na eriya shine kewayon mitar aiki inda ɗaya ko wasu sigogin aikin lantarki na eriya suka cika buƙatun, ana iya amfani da sigogin lantarki daban-daban don auna nisa na mitar mitar.Misali, fadin mitar mitar wanda ya yi daidai da fadin lobe na 3dB ( fadin lobe yana nufin kwana tsakanin maki biyu inda karfin radiation ya ragu da 3dB, wato karfin karfin yana raguwa da rabi, a bangarorin biyu na matsakaicin shugabanci na radiation. na babban lobe), da kuma mitar band nisa inda madaidaicin igiyar igiyar ruwa ta cika wasu buƙatu.Daga cikin su, abin da aka fi amfani da shi shine bandwidth da aka auna ta hanyar rabon igiyar ruwa.
3.Dangantaka tsakanin mitar aiki da girman eriya
A cikin irin wannan matsakaici, saurin yaɗawar igiyoyin lantarki na lantarki ya tabbata (daidai da saurin haske a cikin vacuum, rikodin kamar c≈3 × 108m/s).A cewar c = λf, ana iya ganin tsayin igiyoyin da aka saba da mitar, kuma su biyun su ne kawai alakar da ta dace.
Tsawon eriya ya yi daidai da tsayin igiyar ruwa kuma ya yi daidai da mitar.Wato mafi girman mitar, mafi guntu tsawon zangon, kuma guntuwar eriya za a iya yi.Tabbas, tsawon eriya yawanci ba ya kai tsayin zango ɗaya, amma sau da yawa yana 1/4 tsayi ko 1/2 (yawanci tsawon zangon da ya yi daidai da mitar aiki ta tsakiya ana amfani da shi).Domin lokacin da tsawon madugu ya zama maɓalli na lamba 1/4, mai gudanarwa yana nuna halayen sauti a mitar wannan tsayin.Lokacin da jagorar tsawon ya kasance 1/4 wavelength, yana da jerin halayen resonance, kuma lokacin da tsayin jagoran ya kasance 1/2 wavelength, yana da halaye masu kama da juna.A cikin wannan yanayin resonance, eriya tana haskakawa sosai kuma watsawa da ingantaccen juzu'i yana da girma.Ko da yake radiation na oscillator ya wuce 1/2 na tsawon zango, radiation za ta ci gaba da inganta, amma anti-lokaci radiation na wuce haddi rabo zai haifar da wani sokewa sakamakon, don haka gaba ɗaya tasirin radiation ya lalace.Don haka, eriya gama gari suna amfani da naúrar tsayin oscillator na tsawon zangon 1/4 ko 1/2 zango.Daga cikin su, eriya mai tsayi 1/4 galibi tana amfani da ƙasa a matsayin madubi maimakon eriyar rabin igiyar ruwa.
1/4 eriya na tsawon zango na iya cimma madaidaicin ma'aunin igiyar igiyar ruwa da tasirin amfani ta hanyar daidaita tsararrun, kuma a lokaci guda, yana iya adana sararin shigarwa.Koyaya, eriya na wannan tsayi yawanci suna da ƙarancin riba kuma ba za su iya biyan buƙatun wasu yanayin watsa babban riba ba.A wannan yanayin, yawanci ana amfani da eriya mai tsayi 1/2.
Bugu da kari, an tabbatar da a ka'idar da aiki cewa 5/8 zango tsararru (wannan tsawon yana kusa da 1/2 raƙuman ruwa amma yana da ƙarfi radiation fiye da 1/2 wavelength) ko 5/8 zangon loading tsararru (akwai). za'a iya ƙirƙira ko zaɓin na'ura mai ɗaukar nauyi a rabin nisan nisa daga saman eriya) don samun eriya mai fa'ida mai tsada kuma mafi girma.
Ana iya ganin cewa lokacin da muka san mitar aiki na eriya, za mu iya ƙididdige tsawon madaidaicin madaidaicin, sannan a haɗa tare da ka'idar layin watsawa, yanayin sararin samaniya da buƙatun watsawa, za mu iya kusan sanin tsayin da ya dace na eriyar da ake buƙata. .
Lokacin aikawa: Oktoba-13-2023
