Zikafikatinyanga, funso limene anthu akuda nkhawa nalo kwambiri ndi lakuti "Kodi ma radiation amapezeka bwanji?"Kodi maginito amagetsi opangidwa ndi gwero la siginecha amafalikira bwanji kudzera mu chingwe chotumizira komanso mkati mwa mlongoti, ndipo pamapeto pake "amasiyana" ndi mlongoti kuti apange mafunde aulere.
1. Ma radiation a waya amodzi
Tiyerekeze kuti kachulukidwe kacharge, wofotokozedwa ngati qv (Coulomb/m3), amagawidwa mofanana mu waya wozungulira wokhala ndi gawo lopingasa la a ndi voliyumu ya V, monga momwe tawonetsera pa Chithunzi 1.
Chithunzi 1
Mtengo wokwanira Q mu voliyumu V umayenda molowera z pa liwiro lofanana Vz (m/s).Zitha kutsimikiziridwa kuti kachulukidwe kakali pano Jz pamtanda wa waya ndi:
Jz = qv vz (1)
Ngati waya wapangidwa ndi kondakitala wabwino, kachulukidwe kake ka Js pa waya ndi:
Js = qs vz (2)
Kumene qs ndi kachulukidwe kapamwamba.Ngati waya ndi woonda kwambiri (ngati utali wozungulira ndi 0), zomwe zili mu waya zitha kufotokozedwa motere:
Izi = ql vz (3)
Kumene ql (coulomb/mita) ndi mtengo pa utali wa unit.
Timakhudzidwa makamaka ndi mawaya opyapyala, ndipo mfundo zake zimagwira ntchito pamilandu itatu yomwe ili pamwambapa.Ngati panopo ndi nthawi yosiyana, chochokera ku formula (3) pokhudzana ndi nthawi ndi motere:
(4)
az ndiye kuchuluka kwa ndalama.Ngati waya kutalika ndi l, (4) akhoza kulembedwa motere:
(5)
Equation (5) ndiye ubale woyambira pakati pa apo ndi apo, komanso ubale woyambira wa radiation yamagetsi.Mwachidule, kuti apange ma radiation, payenera kukhala kusinthasintha kwanthawi kapena kuthamangitsa (kapena kutsika) kwa mtengo.Nthawi zambiri timatchula zomwe zikuchitika mu nthawi-harmonic, ndipo mtengo umatchulidwa nthawi zambiri pakanthawi kochepa.Kuti apereke chiwongolero chowonjezera (kapena kuchepetsa), waya ayenera kupindika, kupindika, ndi kusiya.Chiwongolerochi chikayenda mozungulira nthawi, chimapangitsanso kuthamangitsa kwanthawi ndi nthawi (kapena kutsika) kapena kusinthasintha kwanthawi.Chifukwa chake:
1) Ngati mtengowo susuntha, sipadzakhalanso ma radiation komanso ma radiation.
2) Ngati mtengowo ukuyenda mwachangu:
a.Ngati waya ndi wowongoka komanso wopanda malire m'litali, palibe ma radiation.
b.Ngati waya wopindika, wopindidwa, kapena wosapitirira, monga momwe tawonetsera pa Chithunzi 2, pali ma radiation.
3) Ngati chiwongolerocho chikudutsa pakapita nthawi, mtengowo umatulutsa ngakhale waya wowongoka.
Chithunzi 2
Kumvetsetsa kwabwino kwa makina opangira ma radiation kungapezeke poyang'ana gwero la pulsed lomwe limalumikizidwa ndi waya wotseguka womwe ungathe kukhazikitsidwa kudzera mu katundu kumapeto kwake, monga momwe tawonetsera pa Chithunzi 2 (d).Pamene mawaya amapatsidwa mphamvu, zolipiritsa (maelekitironi aulere) mu waya zimayendetsedwa ndi mizere yamagetsi yopangidwa ndi gwero.Pamene zolipiritsa zimachulukitsidwa kumapeto kwa waya ndikutsika (kuthamanga koyipa kofananira ndi kusuntha koyambirira) zikawonetsedwa kumapeto kwake, gawo la radiation limapangidwa kumapeto kwake komanso mbali zonse za waya.Kuchulukitsa kwa milanduyo kumatheka ndi gwero lakunja la mphamvu lomwe limapangitsa kuti ziwongolerezi ziziyenda komanso kutulutsa gawo lomwe limakhudzidwa ndi ma radiation.Kutsika kwa milandu kumapeto kwa waya kumatheka ndi mphamvu zamkati zomwe zimagwirizanitsidwa ndi munda wopangidwa, zomwe zimayambitsidwa ndi kudzikundikira kwa ndalama zowonongeka pamapeto a waya.Mphamvu zamkati zimapeza mphamvu kuchokera pakuwunjika kwa chiwongolero pomwe liwiro lake limatsika mpaka ziro kumapeto kwa waya.Chifukwa chake, kuthamangitsidwa kwa zolipiritsa chifukwa cha kutukuka kwa malo amagetsi komanso kuchepa kwa zolipiritsa chifukwa cha kutha kapena kupindika kwa waya ndi njira zopangira ma radiation a electromagnetic.Ngakhale kachulukidwe kakali pano (Jc) ndi kachulukidwe kachaji (qv) ndi mawu oyambira mu ma equation a Maxwell, mtengowo umawonedwa ngati wofunikira kwambiri, makamaka magawo osakhalitsa.Ngakhale kufotokozerako kwa radiation kumagwiritsidwa ntchito makamaka kumadera osakhalitsa, kumatha kugwiritsidwanso ntchito kufotokozera ma radiation osakhazikika.
Ndiuzeni zingapo zabwino kwambirimankhwala antennaopangidwa ndiRFMISO:
RM-TCR406.4
RM-BCA082-4 (0.8-2GHz)
RM-SWA910-22(9-10GHz)
2. Ma radiation awiri a waya
Lumikizani gwero lamagetsi ku chingwe chotumizira ma kondakitala awiri olumikizidwa ndi mlongoti, monga momwe tawonetsera pa Chithunzi 3(a).Kuyika magetsi pamzere wa waya wawiri kumapanga malo amagetsi pakati pa ma conductor.Mizere yamagetsi yamagetsi imagwira ntchito pa ma elekitironi aulere (osiyanitsidwa mosavuta ndi ma atomu) olumikizidwa ndi kondakitala aliyense ndikuwakakamiza kuti asunthe.Kusuntha kwa ma charger kumapangitsa kuti pakhale mphamvu yamaginito.
Chithunzi 3
Tavomereza kuti mizere yamagetsi imayamba ndi zolipiritsa zabwino ndipo zimatha ndi zolipiritsa.Zachidziwikire, amathanso kuyamba ndi zolipiritsa zabwino ndikumaliza mopanda malire;kapena kuyamba pa infinity ndi kutha ndi milandu zoipa;kapena kupanga malupu otsekedwa omwe samayamba kapena kutha ndi mtengo uliwonse.Mizere ya maginito nthawi zonse imapanga malupu otsekedwa mozungulira ma kondakitala omwe amanyamula pakali pano chifukwa mulibe maginito amagetsi mu physics.Mu masamu ena, maginito ofanana ndi maginito ndi maginito amayambitsidwa kuti asonyeze kuwirikiza pakati pa mayankho okhudza mphamvu ndi magwero a maginito.
Mizere yamagetsi yojambulidwa pakati pa ma conductor awiri imathandizira kuwonetsa kugawa kwacharge.Ngati tikuganiza kuti gwero lamagetsi ndi sinusoidal, tikuyembekeza kuti gawo lamagetsi pakati pa owongolera likhalenso sinusoidal ndi nthawi yofanana ndi gwero.Kuchuluka kwa mphamvu yamagetsi kumayimiridwa ndi kachulukidwe ka mizere yamagetsi, ndipo miviyo imasonyeza mbali yake (yabwino kapena yoipa).Mbadwo wa magetsi ndi maginito osinthasintha nthawi pakati pa ma conductor amapanga mafunde a electromagnetic omwe amafalikira motsatira mzere wotumizira, monga momwe tawonetsera pa Chithunzi 3 (a).Mafunde a electromagnetic amalowa mu mlongoti ndi chiwongolero komanso chofananira.Ngati tichotsa gawo la dongosolo la antenna, monga momwe tawonetsera pa Chithunzi 3 (b), mafunde aulere amatha kupangidwa ndi "kulumikiza" malekezero otseguka a mizere yamagetsi (yosonyezedwa ndi mizere ya madontho).Mafunde omasuka amakhalanso nthawi, koma nthawi zonse P0 imayenda panja pa liwiro la kuwala ndipo imayenda mtunda wa λ/2 (mpaka P1) mu theka la nthawi.Pafupi ndi mlongoti, gawo lokhazikika la P0 limayenda mwachangu kuposa liwiro la kuwala ndikuyandikira liwiro la kuwala pamalo akutali ndi mlongoti.Chithunzi cha 4 chikuwonetsa magawo amagetsi aulere a λ∕2 mlongoti pa t = 0, t/8, t/4, ndi 3T/8.
Chithunzi 4 Kugawa kwamagetsi kwa λ∕2 mlongoti pa t = 0, t/8, t/4 ndi 3T/8
Sizidziwika momwe mafunde owongolera amasiyanitsidwa ndi mlongoti ndipo potsirizira pake amapangidwa kuti afalikire mu malo aulere.Tikhoza kuyerekezera mafunde otsogolera ndi omasuka ndi mafunde a madzi, omwe angayambidwe ndi mwala wogwetsedwa m'madzi abata kapena m'njira zina.Kusokonezeka m'madzi kukayamba, mafunde amadzi amapangidwa ndikuyamba kufalikira kunja.Ngakhale chipwirikiticho chitayima, mafunde sasiya koma akupitiriza kufalikira patsogolo.Ngati chisokonezocho chikupitirira, mafunde atsopano amapangidwa nthawi zonse, ndipo kufalikira kwa mafundewa kumatsalira kumbuyo kwa mafunde ena.
N'chimodzimodzinso ndi mafunde a electromagnetic opangidwa ndi kusokonezeka kwa magetsi.Ngati kusokonezeka kwamagetsi koyambirira kochokera kumagwero ndi kwakanthawi kochepa, mafunde a electromagnetic omwe amapangidwa amafalikira mkati mwa chingwe chotumizira, kenaka lowetsani mlongoti, ndipo pamapeto pake amawala ngati mafunde aulere, ngakhale chisangalalo sichikupezeka (monga mafunde amadzi). ndi chisokonezo chomwe adachipanga).Ngati kusokonezeka kwa magetsi kukupitirirabe, mafunde a electromagnetic amakhalapo mosalekeza ndipo amatsatira kwambiri kumbuyo kwawo panthawi yofalitsa, monga momwe tawonetsera mu mlongoti wa biconical womwe ukuwonetsedwa mu Chithunzi 5. Pamene mafunde a electromagnetic ali mkati mwa mizere yopatsirana ndi tinyanga, kukhalapo kwawo kumagwirizana ndi kukhalapo kwa magetsi. mtengo mkati mwa conductor.Komabe, mafunde akamawotchedwa, amapanga chipika chotsekedwa ndipo palibe malipiro oti apitirize kukhalapo.Izi zikutifikitsa ku mfundo yakuti:
Kusangalatsa kwamunda kumafuna kufulumizitsa ndi kutsika kwa mtengowo, koma kukonza munda sikufuna kuthamangitsidwa ndi kutsika kwa mtengowo.
Chithunzi 5
3. Dipole Radiation
Timayesa kufotokoza njira yomwe mizere yamagetsi yamagetsi imachoka ku mlongoti ndikupanga mafunde omasuka, ndikutenga antenna ya dipole monga chitsanzo.Ngakhale kuti ndi kufotokozera kosavuta, kumathandizanso kuti anthu azitha kuona mwachidwi m'badwo wa mafunde aulere.Chithunzi 6(a) chikuwonetsa mizere yamagetsi yomwe imapangidwa pakati pa mikono iwiri ya dipole pamene mizere yamagetsi imayenda panja ndi λ∕4 m'gawo loyamba la kuzungulira.Kwa chitsanzo ichi, tiyeni tiyerekeze kuti chiwerengero cha mizere yamagetsi yopangidwa ndi 3. Mugawo lotsatira la kuzungulira, mizere itatu yoyambirira yamagetsi imasuntha wina λ∕4 (chiwerengero cha λ∕2 kuchokera poyambira), ndipo kachulukidwe kawo pa kondakitala akuyamba kuchepa.Itha kuganiziridwa kuti imapangidwa poyambitsa milandu yotsutsana, yomwe imachotsa zolipiritsa pa kondakitala kumapeto kwa theka loyamba la kuzungulira.Mizere yamagetsi yopangidwa ndi zolipiritsa zotsutsana ndi 3 ndikuyenda mtunda wa λ∕4, womwe ukuimiridwa ndi mizere yamadontho mu Chithunzi 6(b).
Chotsatira chake ndi chakuti pali mizere itatu yopita pansi yamagetsi mumtunda woyamba λ∕4 ndi nambala yofanana ya mizere yopita kumtunda yamagetsi mumtunda wachiwiri λ∕4.Popeza palibe ndalama zaukonde pa antenna, mizere yamagetsi yamagetsi iyenera kukakamizidwa kuti isiyanitse ndi kondakitala ndikuphatikizana kuti ikhale yotsekedwa.Izi zikuwonetsedwa mu Chithunzi 6 (c).Mu theka lachiwiri, ndondomeko yofanana ya thupi imatsatiridwa, koma dziwani kuti njirayo ndi yosiyana.Pambuyo pake, ndondomekoyi imabwerezedwa ndikupitirira mpaka kalekale, ndikupanga kugawa kwamagetsi kofanana ndi Chithunzi 4.
Chithunzi 6
Kuti mudziwe zambiri za antennas, chonde pitani:
Nthawi yotumiza: Jun-20-2024
