Idan aka zoantennas, Tambayar da mutane suka fi damuwa da ita ita ce "Yaya ake samun radiation a zahiri?"Ta yaya filin lantarki da aka samar ta hanyar siginar siginar ke yaduwa ta hanyar layin watsawa da kuma cikin eriya, kuma a karshe ya "rabe" daga eriya don samar da igiyar sarari kyauta.
1. Single waya radiation
Bari mu ɗauka cewa yawan cajin, wanda aka bayyana a matsayin qv (Coulomb / m3), an rarraba shi daidai a cikin waya madauwari tare da yanki mai giciye na a da ƙarar V, kamar yadda aka nuna a hoto 1.
Hoto 1
Jimlar cajin Q a ƙarar V yana motsawa a cikin alkiblar z a daidaitaccen gudu Vz (m/s).Ana iya tabbatar da cewa yawan Jz na yanzu akan sashin giciye na waya shine:
Jz = qv vz (1)
Idan wayar an yi ta ne da ingantacciyar jagora, ƙimar Js na yanzu akan saman waya shine:
Js = qs vz (2)
Inda qs shine yawan cajin saman.Idan wayar tana da bakin ciki sosai (madaidaici, radius 0 ne), ana iya bayyana halin yanzu a cikin wayar kamar:
Iz = ql vz (3)
Inda ql (coulomb/mita) shine cajin kowane tsayin raka'a.
Mun fi damuwa da ƙananan wayoyi, kuma ƙarshen ya shafi shari'o'i uku na sama.Idan halin yanzu ya bambanta lokaci, abin da aka samo asali (3) dangane da lokaci shine kamar haka:
(4)
az shine saurin caji.Idan tsawon waya ya kasance l, (4) za a iya rubuta kamar haka:
(5)
Equation (5) shine ainihin alaƙar da ke tsakanin halin yanzu da caji, da kuma ainihin alaƙar radiation na lantarki.A taƙaice, don samar da radiation, dole ne a sami canjin lokaci ko haɓakawa (ko ragewa) na caji.Yawancin lokaci muna ambaton halin yanzu a aikace-aikacen jituwa-lokaci, kuma ana yawan ambaton caji a aikace-aikacen wucin gadi.Domin samar da hanzarin caji (ko ragewa), wayar dole ne a lanƙwasa, naɗewa, kuma a daina.Lokacin da cajin ya motsa a cikin motsi na lokaci-lokaci, zai kuma samar da hanzarin caji na lokaci-lokaci (ko ragewa) ko canjin lokaci na halin yanzu.Saboda haka:
1) Idan cajin bai motsa ba, ba za a sami halin yanzu ba kuma babu radiation.
2) Idan cajin yana motsawa cikin sauri akai-akai:
a.Idan waya madaidaiciya kuma tsayinsa mara iyaka, babu radiation.
b.Idan wayar ta lanƙwasa, naɗewa, ko kuma ta daina, kamar yadda aka nuna a hoto na 2, akwai radiation.
3) Idan cajin yayi oscillate akan lokaci, cajin zai haskaka koda kuwa waya ta mike.
Hoto 2
Za a iya samun kyakkyawar fahimta ta hanyar hasken wuta ta hanyar kallon tushen bugun da aka haɗa da buɗaɗɗen waya wanda za a iya yin ƙasa ta hanyar kaya a ƙarshensa, kamar yadda aka nuna a hoto na 2 (d).Lokacin da wayar ta fara samun kuzari, ana saita cajin (electrons kyauta) a cikin wayar ta hanyar layin wutar lantarki da aka samar.Yayin da ake ƙara ƙarar cajin a ƙarshen tushen waya kuma an rage (ƙaramar haɓakawa mara kyau dangane da motsi na ainihi) lokacin da aka nuna a ƙarshensa, ana haifar da filin radiation a iyakarsa da sauran waya.Ana aiwatar da hanzarin cajin ta hanyar tushen ƙarfi na waje wanda ke saita cajin a cikin motsi kuma ya samar da filin radiation mai alaƙa.Ƙaddamar da cajin a ƙarshen waya yana cika ta hanyar dakarun ciki da ke da alaƙa da filin da aka jawo, wanda ke haifar da tarin cajin da aka tattara a ƙarshen waya.Sojojin cikin gida suna samun kuzari daga tarin caji yayin da saurin sa ya ragu zuwa sifili a ƙarshen waya.Don haka, haɓakar cajin saboda tashin hankali na filin lantarki da kuma raguwar cajin saboda katsewa ko lanƙwasa mai laushi na igiyar waya shine hanyoyin samar da hasken lantarki.Ko da yake duka yawan halin yanzu (Jc) da ƙimar caji (qv) sharuɗɗan tushe ne a cikin equations Maxwell, ana ɗaukar cajin mafi mahimmancin adadi, musamman ga filayen wucin gadi.Ko da yake ana amfani da wannan bayanin na radiation musamman don jahohin wucin gadi, ana kuma iya amfani da shi don bayyana radiyo mai tsayi.
Ba da shawarar mafi kyau da yawasamfuran eriyakerarre taRFMISO:
RM-TCR406.4
RM-BCA082-4 (0.8-2GHz)
RM-SWA910-22(9-10GHz)
2. Radiyon waya biyu
Haɗa tushen wutar lantarki zuwa layin watsa madugu biyu da aka haɗa da eriya, kamar yadda aka nuna a hoto 3(a).Yin amfani da wutar lantarki zuwa layin waya biyu yana haifar da wutar lantarki tsakanin masu gudanarwa.Layukan filayen lantarki suna aiki akan na'urorin lantarki masu kyauta (a sauƙaƙe raba su da atoms) waɗanda aka haɗa zuwa kowane madubi kuma suna tilasta musu motsawa.Motsi na caji yana haifar da halin yanzu, wanda kuma ya haifar da filin maganadisu.
Hoto 3
Mun yarda cewa layukan filin lantarki suna farawa da caji mai kyau kuma suna ƙare da caji mara kyau.Tabbas, kuma suna iya farawa tare da kyawawan zarge-zarge kuma su ƙare a marar iyaka;ko fara a marar iyaka kuma ƙare tare da caji mara kyau;ko samar da madaukai rufaffiyar waɗanda ba su farawa ko ƙare tare da kowane caji.Layukan filin maganadisu koyaushe suna yin rufaffiyar madaukai a kusa da madugu masu ɗaukar nauyi saboda babu cajin maganadisu a kimiyyar lissafi.A cikin wasu ƙididdiga na lissafi, daidaitattun cajin maganadisu da igiyoyin maganadisu ana gabatar da su don nuna duality tsakanin hanyoyin magance ƙarfi da tushen maganadisu.
Layukan wutar lantarki da aka zana tsakanin madugu biyu suna taimakawa wajen nuna rarraba caji.Idan muka ɗauka cewa tushen wutar lantarki sinusoidal ne, muna sa ran filin lantarki tsakanin masu gudanarwa shima ya zama sinusoidal tare da lokaci daidai da na tushen.Girman dangi na ƙarfin filin lantarki yana wakiltar girman layin wutar lantarki, kuma kiban suna nuna alamar dangi (tabbatacce ko korau).Ƙirƙirar filayen lantarki da na maganadisu masu bambanta lokaci tsakanin masu gudanarwa suna samar da igiyoyin lantarki da ke yaduwa tare da layin watsawa, kamar yadda aka nuna a cikin hoto 3 (a).Wutar lantarki tana shiga eriya tare da caji da kuma daidaitaccen halin yanzu.Idan muka cire wani ɓangare na tsarin eriya, kamar yadda aka nuna a Hoto na 3 (b), za a iya samar da igiyar sararin samaniya ta hanyar "haɗa" buɗewar ƙarshen layin wutar lantarki (wanda aka nuna ta layukan da aka ɗora).Gudun sararin sararin samaniya shima lokaci-lokaci ne, amma madaidaicin lokaci P0 yana motsawa waje cikin saurin haske kuma yana tafiya tazarar λ/2 (zuwa P1) cikin rabin lokaci.Kusa da eriya, madaidaicin lokaci-lokaci P0 yana motsawa da sauri fiye da saurin haske kuma yana kusanci saurin haske a wurare masu nisa daga eriya.Hoto 4 yana nuna rarraba filin lantarki kyauta na eriya λ∕2 a t = 0, t/8, t/4, da 3T/8.
Hoto 4 Rarraba filin lantarki kyauta na eriya λ∕2 a t = 0, t/8, t/4 da 3T/8
Ba a san yadda aka raba raƙuman ruwa masu shiryarwa daga eriya ba kuma a ƙarshe an kafa su don yaduwa cikin sarari kyauta.Za mu iya kwatanta raƙuman sararin samaniya mai shiryarwa da kyauta da raƙuman ruwa, wanda zai iya haifar da shi ta hanyar wani dutse da aka jefa a cikin ruwa mai natsuwa ko kuma ta wasu hanyoyi.Da zarar tashin hankali a cikin ruwa ya fara, ana haifar da raƙuman ruwa kuma suna fara yaduwa a waje.Ko da hargitsin ya tsaya, igiyoyin ruwa ba su daina amma suna ci gaba da yaduwa gaba.Idan hargitsin ya ci gaba, ana haifar da sabbin raƙuman ruwa akai-akai, kuma yaduwar waɗannan raƙuman ruwa suna bayan sauran raƙuman ruwa.
Haka lamarin yake ga igiyoyin lantarki da ke haifar da hargitsin lantarki.Idan hargitsin wutar lantarki na farko daga tushen ya kasance na ɗan gajeren lokaci, igiyoyin lantarki da aka haifar suna yaduwa a cikin layin watsawa, sannan shigar da eriya, sannan a ƙarshe suna haskakawa azaman raƙuman sarari kyauta, kodayake tashin hankali ba ya nan (kamar yadda igiyar ruwa ta kasance. da hargitsin da suka haifar).Idan hargitsin wutar lantarki ya ci gaba, igiyoyin lantarki suna ci gaba da kasancewa kuma suna bin bayansu yayin yaduwa, kamar yadda aka nuna a cikin eriyar biconical da aka nuna a hoto na 5. Lokacin da igiyoyin lantarki ke cikin layin watsawa da eriya, kasancewarsu yana da alaƙa da wanzuwar lantarki. caji a cikin madugu.Duk da haka, lokacin da raƙuman ruwa ke haskakawa, suna samar da rufaffiyar madauki kuma babu wani caji don kiyaye wanzuwar su.Wannan ya kai mu ga matsayar cewa:
Jin daɗin filin yana buƙatar haɓakawa da rage cajin, amma kiyaye filin baya buƙatar haɓakawa da rage cajin.
Hoto 5
3. Dipole Radiation
Muna ƙoƙarin yin bayanin hanyar da layukan filayen lantarki ke fita daga eriya kuma su samar da raƙuman sararin samaniya, kuma mu ɗauki eriyar dipole a matsayin misali.Ko da yake bayani ne mai sauƙi, yana kuma baiwa mutane damar ganin haƙiƙanin haɓakar raƙuman sararin samaniya.Hoto 6 (a) yana nuna layin wutar lantarki da aka samar tsakanin hannayen biyu na dipole lokacin da layin wutar lantarki ke motsawa waje ta λ∕4 a farkon kwata na zagaye.Don wannan misalin, bari mu ɗauka cewa adadin layin wutar lantarki da aka kafa shine 3. A cikin kwata na gaba na sake zagayowar, ainihin layin wutar lantarki guda uku yana motsa wani λ∕4 (jimlar λ∕2 daga farkon farawa), kuma yawan cajin akan mai gudanarwa ya fara raguwa.Ana iya la'akari da samuwa ta hanyar gabatar da cajin da aka saba, wanda ya soke cajin da aka yi a kan mai gudanarwa a ƙarshen rabin farko na sake zagayowar.Layukan wutar lantarki da aka samar ta hanyar cajin kishiyar su ne 3 kuma suna matsar da nisa na λ∕4, wanda ke wakilta da layukan dige-dige a cikin hoto 6(b).
Sakamakon ƙarshe shine cewa akwai layukan filayen lantarki guda uku a ƙasa a cikin tazarar λ∕4 na farko da adadin layukan filayen wutar lantarki iri ɗaya a cikin tazarar λ∕4 na biyu.Tunda babu cajin gidan yanar gizo akan eriya, dole ne a tilasta layin filayen lantarki su rabu da madubi kuma a haɗa su tare don ƙirƙirar madauki mai rufaffiyar.Ana nuna wannan a hoto na 6 (c).A cikin rabi na biyu, ana bin tsarin jiki iri ɗaya, amma lura cewa shugabanci ya sabawa.Bayan haka, ana maimaita tsarin kuma yana ci gaba har abada, yana samar da rarraba wutar lantarki mai kama da hoto na 4.
Hoto 6
Don ƙarin koyo game da eriya, da fatan za a ziyarci:
Lokacin aikawa: Juni-20-2024
