Uma kufikaizimpondo, umbuzo abantu abakhathazeke kakhulu ngawo uthi "Ingabe imisebe ifinyelelwa kanjani ngempela?"Ingabe inkambu kazibuthe kagesi ekhiqizwe umthombo wesignali isakazeka kanjani ngomugqa wokudlulisela nangaphakathi kwe-antenna, futhi ekugcineni "ihlukanise" ne-antenna ukuze yakhe igagasi lesikhala samahhala.
1. Imisebe yocingo olulodwa
Ake sicabange ukuthi ukuminyana kokushaja, okuvezwa njenge-qv (Coulomb/m3), kusakazwa ngokufanayo ngocingo oluyisiyingi olunendawo ephambanayo engu-a kanye nevolumu engu-V, njengoba kukhonjisiwe kuMfanekiso 1.
Umfanekiso 1
Isamba sokushajwa okungu-Q kuvolumu V sihamba siye ku-z ngesivinini esilinganayo esingu-Vz (m/s).Kungafakazelwa ukuthi ukuminyana kwamanje kwe-Jz engxenyeni ephambene yocingo yile:
Jz = qv vz (1)
Uma ucingo lwenziwe nge-conductor ekahle, ukuminyana kwamanje Js endaweni yocingo yile:
Js = qs vz (2)
Lapho qs kukhona ukuminyana kokushaja okungaphezulu.Uma ucingo luncane kakhulu (okungcono, irediyasi ingu-0), i-current in the wire ingavezwa ngokuthi:
Iz = ql vz (3)
Lapho i-ql (coulomb/imitha) iyishaja ngobude beyunithi ngayinye.
Sikhathazeke kakhulu ngezintambo ezincane, futhi iziphetho zisebenza kulezi zimo ezintathu ezingenhla.Uma isimanje sishintsha isikhathi, okuphuma kufomula (3) maqondana nesikhathi kungokulandelayo:
(4)
i-az ukusheshisa ukushaja.Uma ubude bentambo bungu-l, (4) bungabhalwa kanje:
(5)
I-equation (5) iwubudlelwane obuyisisekelo phakathi kwamanje nokushaja, kanye nobudlelwano obuyisisekelo bemisebe kazibuthe kagesi.Kalula nje, ukuze kukhiqizwe imisebe, kufanele kube khona isikhathi esishintshashintshayo samanje noma ukusheshisa (noma ukwehla) kwenkokhelo.Sivamise ukusho izinhlelo zokusebenza zamanje ezihambisana nesikhathi, futhi inkokhiso ivame ukukhulunywa ngayo ezinhlelweni zesikhashana.Ukuze kukhiqizwe ukusheshisa ukushaja (noma ukuncipha), intambo kufanele igotshwe, igoqwe, futhi ingaqhubeki.Uma inkokhiso inyakaza ngokuhamba kwesikhathi, izophinda ikhiqize ukusheshisa ukushaja ngezikhathi ezithile (noma ukwehla) noma ukwahluka kwesikhathi.Ngakho-ke:
I-1) Uma ukushaja kunganyakazi, ngeke kube khona okwamanje futhi kungabikho imisebe.
2) Uma ukushaja kuhamba ngesivinini esingaguquki:
a.Uma intambo iqondile futhi ingapheli ngobude, ayikho imisebe.
b.Uma ucingo lugobile, lugoqiwe, noma lungaqhubeki, njengoba kuboniswe kuMfanekiso 2, kunemisebe.
3) Uma ukushaja kugeleza ngokuhamba kwesikhathi, ukushaja kuzokhanya ngisho noma ucingo luqondile.
Umfanekiso 2
Ukuqonda okuseqophelweni eliphezulu kwendlela yokukhipha imisebe kungatholwa ngokubheka umthombo we-pulsed oxhunywe ocingweni oluvulekile olungamiswa ngomthwalo ekugcineni kwawo ovulekile, njengoba kukhonjisiwe kuMfanekiso 2(d).Lapho intambo iqala amandla, amashaji (ama-electron amahhala) ocingweni ahlelwa anyakaze izintambo zikagesi ezikhiqizwe umthombo.Njengoba izindleko zisheshiswa ekugcineni komthombo wentambo futhi zehliswa (ukusheshisa okunegethivu okuhlobene nokunyakaza kwasekuqaleni) uma kuboniswa ekupheleni kwakho, inkambu yokukhishwa kwemisebe ikhiqizwa emaphethelweni ayo kanye nakuyo yonke intambo.Ukusheshiswa kwezindleko kufezwa umthombo wamandla wangaphandle obeka izindleko ziqhubeke futhi ukhiqize inkambu yemisebe ehlobene.Ukwehliswa kwezindleko emaphethelweni ocingo kufezwa amandla angaphakathi ahlotshaniswa nensimu eyenziwe, okubangelwa ukuqoqwa kwezindleko ezigxiliwe ekugcineni kocingo.Amandla angaphakathi azuza amandla kusukela ekuqoqweni kweshaji njengoba ijubane layo lehla libe yiziro ekugcineni kwentambo.Ngakho-ke, ukusheshisa kwezindleko ngenxa yokuvuswa kwensimu kagesi kanye nokwehla kwezindleko ngenxa yokungaqhubeki noma ijika elibushelelezi le-impedance yocingo yizindlela zokukhiqiza imisebe ye-electromagnetic.Nakuba kokubili ukuminyana kwamanje (Jc) kanye nokuminyana kweshaji (qv) kuyimibandela yomthombo ezibalweni zika-Maxwell, inkokhiso ibhekwa njengenani elibaluleke kakhulu, ikakhulukazi ezinkambu zesikhashana.Nakuba le ncazelo yemisebe isetshenziswa kakhulu ezimeni zesikhashana, ingasetshenziswa futhi ukuchaza imisebe yesimo esingashintshi.
Ncoma ezimbalwa ezinhle kakhuluimikhiqizo ye-antennaekhiqizwa nguI-RFMISO:
RM- I-TCR406.4
RM-BCA082-4(0.8-2GHz)
I-RM-SWA910-22(9-10GHz)
2. Imisebe yezintambo ezimbili
Xhuma umthombo kagesi kulayini wokudlulisa wamakhondatha amabili oxhunywe othingo, njengoba kubonisiwe kuMfanekiso 3(a).Ukusebenzisa i-voltage kulayini wezintambo ezimbili kukhiqiza inkambu kagesi phakathi kwamakhondakta.Imigqa yenkundla kagesi isebenza kuma-electron amahhala (ahlukaniswe kalula nama-athomu) axhunywe ku-conductor ngayinye futhi awaphoqe ukuthi ahambe.Ukuhamba kwamashaji kukhiqiza amandla amanje, wona akhiqiza insimu kazibuthe.
Umfanekiso 3
Samukele ukuthi izintambo zikagesi ziqala ngamashaji avumayo futhi zigcine ngamashaji angemahle.Yebo, bangaqala futhi ngamashaji avumayo futhi bagcine ngokungapheli;noma uqale kokungapheli futhi uphethe ngamashaji angemahle;noma enze amaluphu avaliwe angaqali futhi angaqedi nganoma yimaphi amashaji.Imigqa yenkambu kazibuthe ihlala yenza izihibe ezivaliwe ezizungeze amakhondaktha aphethe manje ngoba awekho amashaji kazibuthe ku-physics.Kwamanye amafomula ezibalo, ukushaja kazibuthe alinganayo namaza kazibuthe kuyethulwa ukuze kuboniswe ububili phakathi kwezixazululo ezifaka amandla nemithombo kazibuthe.
Imigqa yenkundla kagesi edwetshwe phakathi kwamakhondakta amabili isiza ukukhombisa ukusatshalaliswa kwenkokhiso.Uma sicabanga ukuthi umthombo wamandla kagesi uyi-sinusoidal, silindele ukuthi inkambu kagesi phakathi kwamakhondatha nayo ibe yi-sinusoidal nesikhathi esilingana nesomthombo.Ubukhulu obuhlobene bamandla kagesi bumelwe ukuminyana kwemigqa yensimu kagesi, futhi imicibisholo ikhombisa isiqondiso esihlobene (esihle noma esibi).Isizukulwane sezinkambu zikagesi nezikazibuthe ezishintshashintsha isikhathi phakathi kwamakhondakta sakha igagasi kagesi elisakazeka eduze komugqa wokudlulisela, njengoba kuboniswe kuMfanekiso 3(a).I-electromagnetic wave ingena ku-antenna neshaje kanye namandla ahambisanayo.Uma sisusa ingxenye yesakhiwo se-antenna, njengoba kukhonjisiwe kuMfanekiso 3(b), igagasi lesikhala esikhululekile lingakhiwa "ngokuxhuma" iziphetho ezivulekile zemigqa yenkambu kagesi (eboniswa imigqa enamachashazi).Igagasi lesikhala esikhululekile liphinde libe ngezikhathi ezithile, kodwa iphuzu lesigaba esingaguquki u-P0 liya ngaphandle ngesivinini sokukhanya futhi lihamba ibanga elingu-λ/2 (kuya ku-P1) ngesigamu sesikhathi.Eduze kwe-antenna, iphoyinti lesigaba esingaguquki u-P0 lihamba ngokushesha kunejubane lokukhanya futhi lisondela kwijubane lokukhanya ezindaweni ezikude nothi.Umfanekiso 4 ubonisa ukusatshalaliswa kwenkambu kagesi yendawo yamahhala ye-λ∕2 antenna kokuthi t = 0, t/8, t/4, kanye 3T/8.
Umfanekiso 4 Isikhala samahhala sokusabalalisa inkambu kagesi ye-λ∕2 antenna kokuthi t = 0, t/8, t/4 kanye 3T/8
Akwaziwa ukuthi amagagasi aqondiswayo ahlukaniswa kanjani ne-antenna futhi ekugcineni akhiwe ukuze asakazeke endaweni ekhululekile.Singaqhathanisa amaza esikhala aqondiswayo nakhululekile namaza amanzi, angabangelwa itshe eliwela emanzini azolile noma ngezinye izindlela.Lapho ukuphazamiseka emanzini kuqala, amagagasi amanzi akhiqizwa futhi aqala ukusabalala ngaphandle.Ngisho noma ukuphazamiseka kuma, amagagasi awami kodwa ayaqhubeka nokusabalala aye phambili.Uma ukuphazamiseka kuqhubeka, amagagasi amasha akhiqizwa njalo, futhi ukusabalala kwala magagasi kubambezeleka ngemuva kwamanye amagagasi.
Okufanayo kuyiqiniso ngamaza kagesi akhiqizwa ukuphazamiseka kukagesi.Uma ukuphazamiseka kokuqala kukagesi okuvela emthonjeni okwesikhathi esifushane, amaza kagesi akhiqizwe asakazeka ngaphakathi komugqa wokudlulisela, bese efaka uthi, bese ekugcineni akhazimule njengamaza esikhala samahhala, nakuba ukuthakasela kungasekho (njengamagagasi amanzi. kanye nokuphazamiseka abakudalile).Uma ukuphazamiseka kukagesi kuqhubeka, amagagasi kagesi akhona ngokuqhubekayo futhi alandele eduze kwawo ngesikhathi sokusakazeka, njengoba kuboniswe ku-biconical antenna eboniswe kuMfanekiso 5. Uma amaza kagesi engaphakathi kwemigqa yokudlulisela kanye nezimpondo, ubukhona bawo buhlobene nokuba khona kukagesi. ukushaja ngaphakathi ku-conductor.Nokho, lapho amagagasi ekhipha imisebe, akha iluphu elivalekile futhi akukho nkokhelo yokulondoloza ukuphila kwawo.Lokhu kusiholela esiphethweni sokuthi:
Ukuvuswa kwenkundla kudinga ukusheshisa nokwehliswa kwenkokhelo, kodwa ukugcinwa kwenkundla akudingi ukusheshisa nokwehliswa kwenkokhelo.
Umfanekiso 5
3. I-Dipole Radiation
Sizama ukuchaza indlela olayini benkambu kagesi abahlukana ngayo othini bese benza amagagasi esikhala esikhululekile, bese sithatha i-dipole antenna njengesibonelo.Nakuba kuyincazelo eyenziwe lula, futhi yenza abantu bakwazi ukubona ngokunembile ukukhiqizwa kwamagagasi esikhala esikhululekile.Umfanekiso 6(a) ubonisa imigqa yenkundla kagesi ekhiqizwa phakathi kwezingalo ezimbili ze-dipole lapho imigqa yenkambu kagesi iphumela ngaphandle ngo-λ∕4 engxenyeni yokuqala yomjikelezo.Kulesi sibonelo, ake sicabange ukuthi inani lezintambo zikagesi ezakhiwe ngu-3. Kwikota elandelayo yomjikelezo, imigqa yenkambu kagesi yokuqala emithathu ihambisa enye λ∕4 (inani elingu-λ∕2 ukusuka endaweni yokuqala), futhi ukuminyana kokushaja ku-conductor kuqala ukuncipha.Kungabhekwa njengokwakhiwa ngokusungulwa kwamacala aphikisanayo, akhansela amacala kumqhubi ekupheleni kwengxenye yokuqala yomjikelezo.Imigqa yenkambu kagesi ekhiqizwa amashaji aphambene ingu-3 futhi ihambisa ibanga elingu-λ∕4, elimelelwa imigqa enamachashazi kumfanekiso 6(b).
Umphumela wokugcina ukuthi kukhona imigqa yenkambu kagesi emithathu eyehlayo ebangeni lokuqala elithi λ∕4 kanye nenani elifanayo lemigqa yenkambu kagesi ekhuphukayo ebangeni elingu-λ∕4 lesibili.Njengoba ingekho i-net charge ku-antenna, izintambo zikagesi kumele ziphoqeleke ukuthi zihlukane nomqhubi futhi zihlangane ndawonye ukuze zenze iluphu evaliwe.Lokhu kuboniswe kuMfanekiso 6(c).Engxenyeni yesibili, inqubo efanayo yomzimba ilandelwa, kodwa phawula ukuthi isiqondiso siphambene.Ngemva kwalokho, le nqubo iphindaphindiwe futhi iqhubeka ngokungapheli, yakha ukusabalalisa kwensimu kagesi okufana nomfanekiso wesi-4.
Umfanekiso 6
Ukuze ufunde kabanzi ngama-antenna, sicela uvakashele:
Isikhathi sokuthumela: Jun-20-2024
