Uma kukhulunywa ngokuthiama-antenna, umbuzo abantu abakhathazeke kakhulu ngawo uthi "Kufinyelelwa kanjani ngempela imisebe?" Insimu kagesi ekhiqizwa umthombo wesignali isakazeka kanjani ngomugqa wokudlulisa kanye nangaphakathi kwe-antenna, futhi ekugcineni "ihlukane" ne-antenna ukuze yakhe igagasi lesikhala elikhululekile.
1. Imisebe yentambo eyodwa
Ake sithi ubuningi beshaja, obuvezwa njenge-qv (Coulomb/m3), busatshalaliswa ngokulinganayo entanjeni eyindilinga enendawo enqamulayo engu-a kanye nomthamo ongu-V, njengoba kuboniswe kuMfanekiso 1.
Umfanekiso 1
Isamba semali engu-Q ngevolumu u-V sihamba ngendlela ka-z ngesivinini esifanayo u-Vz (m/s). Kungafakazelwa ukuthi i-Jz yamanje engxenyeni yentambo yile:
Jz = qv vz (1)
Uma ucingo lwenziwe ngomqhubi ofanele, i-Js yamanje ebusweni bentambo iwukuthi:
Js = qs vz (2)
Lapho i-qs iwubuningi beshaja engaphezulu. Uma intambo incane kakhulu (okungcono kakhulu, i-radius ingu-0), ugesi osentanjeni ungachazwa kanje:
Iz = ql vz (3)
Lapho i-ql (coulomb/meter) iyishaji ngobude beyunithi ngayinye.
Sikhathazeke kakhulu ngezintambo ezincane, futhi iziphetho zisebenza ezimweni ezintathu ezingenhla. Uma ugesi ushintshashintsha ngesikhathi, i-derivative yefomula (3) maqondana nesikhathi yile elandelayo:
(4)
i-az ukusheshisa ishaja. Uma ubude bentambo bungu-l, (4) bungabhalwa kanje:
(5)
I-equation (5) ubuhlobo obuyisisekelo phakathi kwamandla kagesi kanye nokushaja, kanye nobudlelwano obuyisisekelo bokukhanya kwe-electromagnetic. Kalula nje, ukuze kukhiqizwe imisebe, kumele kube khona amandla kagesi ashintshashintshayo ngesikhathi noma ukusheshisa (noma ukwehla kwejubane) kweshaja. Sivame ukukhuluma ngamandla kagesi kuzinhlelo zokusebenza ze-harmonic zesikhathi, futhi ishaja ivame ukukhulunywa ngayo kuzinhlelo zokusebenza zesikhashana. Ukuze kukhiqizwe ukusheshisa kweshaja (noma ukwehla kwejubane), ucingo kumele lugotshwe, lugoqwe, futhi lungaqhubeki. Lapho ishaja ishintshashintsha ekunyakazeni kwe-harmonic yesikhathi, izophinde ikhiqize ukusheshisa kweshaja okuvamile (noma ukwehla kwejubane) noma amandla kagesi ashintshashintshayo ngesikhathi. Ngakho-ke:
1) Uma ishaja ingahambi, ngeke kube khona ugesi futhi ngeke kube khona imisebe.
2) Uma ukushaja kuhamba ngesivinini esingaguquki:
a. Uma ucingo luqondile futhi lungenamkhawulo ngobude, akukho misebe.
b. Uma ucingo lugobile, lugoqiwe, noma lungaqhubeki, njengoba kuboniswe kuMfanekiso 2, kukhona imisebe.
3) Uma ishaja ishintshashintsha ngokuhamba kwesikhathi, ishaja izokhipha ukukhanya ngisho noma intambo iqondile.
Umfanekiso 2
Ukuqonda okubalulekile kwendlela yokukhipha imisebe kungatholakala ngokubheka umthombo ocindezelwe oxhunywe kucingo oluvulekile olungasekelwa ngomthwalo ekugcineni kwalo okuvulekile, njengoba kuboniswe kuMfanekiso 2(d). Lapho ucingo luqala ukunikezwa amandla, amashaja (ama-electron amahhala) kucingo aqaliswa ukunyakaza yimigqa yensimu kagesi ekhiqizwa umthombo. Njengoba amashaja esheshiswa ekugcineni komthombo wentambo futhi ehla (ukusheshiswa okungekuhle uma kuqhathaniswa nokunyakaza kokuqala) lapho kubonakala ekugcineni kwalo, insimu yemisebe ikhiqizwa emaphethelweni alo kanye nakwenye ingxenye yentambo. Ukusheshiswa kwamacala kufezwa umthombo wangaphandle wamandla obeka amashaja ekunyakaza futhi akhiqize insimu yemisebe ehambisanayo. Ukusheshiswa kwamacala emaphethelweni entambo kufezwa ngamandla angaphakathi ahlotshaniswa nensimu ebangelwayo, okubangelwa ukuqongelela kwamacala agxilile emaphethelweni entambo. Amandla angaphakathi athola amandla ekuqongeleleni kweshaja njengoba ijubane layo lehla laya ku-zero emaphethelweni entambo. Ngakho-ke, ukusheshisa kwamacala ngenxa yokuvuselelwa kwensimu kagesi kanye nokwehla kwamacala ngenxa yokungaqhubeki noma ukugoba okubushelelezi kwe-wire impedance kuyizindlela zokukhiqiza imisebe kagesi. Nakuba kokubili ubuningi bamanje (Jc) kanye nobuningi beshaja (qv) kuyimigomo yomthombo ezibalweni zikaMaxwell, ishaja ibhekwa njengenani eliyisisekelo, ikakhulukazi kumasimu esikhashana. Nakuba le ncazelo yemisebe isetshenziswa kakhulu ezimweni zesikhashana, ingasetshenziswa futhi ukuchaza imisebe yesimo esizinzile.
Ncoma eziningana ezinhle kakhuluimikhiqizo ye-antennaekhiqizwe yi-I-RFMISO:
RM-TCR406.4
RM-BCA082-4 （0.8-2GHz)
RM-SWA910-22(9-10GHz)
2. Imisebe enezintambo ezimbili
Xhuma umthombo we-voltage entanjeni yokudlulisa yama-conductor amabili exhunywe ku-antenna, njengoba kuboniswe kuMfanekiso 3(a). Ukusebenzisa i-voltage entanjeni yama-wire amabili kudala insimu kagesi phakathi kwama-conductor. Imigqa yensimu kagesi isebenza kuma-electron akhululekile (ahlukaniswe kalula kuma-athomu) axhunywe ku-conductor ngamunye futhi awaphoqe ukuba ahambe. Ukunyakaza kwama-charges kudala ugesi, okuholela ekukhiqizeni insimu yamagnetic.
Umfanekiso 3
Sikwamukele ukuthi imigqa yensimu kagesi iqala ngamashaja amahle futhi iphele ngamashaja amabi. Vele, ingaqala futhi ngamashaja amahle futhi iphele ngokungabi namkhawulo; noma iqale ngokungabi namkhawulo futhi iphele ngamashaja amabi; noma yakhe ama-loop avaliwe angaqali futhi angapheli ngamashaja. Imigqa yensimu yamagnetic ihlala yakha ama-loop avaliwe azungeze abaqhubi abathwala ugesi ngoba azikho izindleko zamagnetic ku-physics. Kwamanye amafomula ezibalo, amashaja anamandla alinganayo kanye nemisinga yamagnetic afakwa ukuze kuboniswe ubumbano phakathi kwezixazululo ezihilela amandla nemithombo yamagnetic.
Imigqa yensimu kagesi edwetshwe phakathi kwabaqhubi ababili isiza ekuboniseni ukusatshalaliswa kweshaja. Uma sicabanga ukuthi umthombo we-voltage uyi-sinusoidal, silindele ukuthi insimu kagesi ephakathi kwabaqhubi nayo ibe yi-sinusoidal enesikhathi esilingana nesomthombo. Ubukhulu obuhlobene bamandla ensimu kagesi bumelelwa ubuningi bemigqa yensimu kagesi, futhi imicibisholo ikhombisa isiqondiso esihlobene (esihle noma esibi). Ukukhiqizwa kwamasimu kagesi namagnetic ashintshashintshayo ngesikhathi phakathi kwabaqhubi kwakha igagasi le-electromagnetic elisakazeka emgqeni wokudlulisa, njengoba kuboniswe kuMfanekiso 3(a). Igagasi le-electromagnetic lingena ku-antenna ngokushaja kanye nogesi ohambisanayo. Uma sisusa ingxenye yesakhiwo se-antenna, njengoba kuboniswe kuMfanekiso 3(b), igagasi lesikhala esikhululekile lingakhiwa "ngokuxhuma" iziphetho ezivulekile zemigqa yensimu kagesi (ekhonjiswe yimigqa enamachashazi). Igagasi lesikhala esikhululekile nalo lihlala likhona, kodwa iphuzu lesigaba esiqhubekayo i-P0 liyaphuma ngesivinini sokukhanya futhi lihamba ibanga elingu-λ/2 (kuya ku-P1) ngesigamu sesikhathi. Eduze kwe-antenna, iphuzu lesigaba esingaguquki i-P0 lihamba ngokushesha kunejubane lokukhanya futhi lisondela kwijubane lokukhanya ezindaweni ezikude ne-antenna. Isibalo 4 sibonisa ukusatshalaliswa kwensimu kagesi yesikhala esikhululekile se-antenna ye-λ∕2 ku-t = 0, t/8, t/4, kanye ne-3T/8.
Umfanekiso 4 Ukusatshalaliswa kwensimu kagesi yesikhala samahhala se-antenna ye-λ∕2 ku-t = 0, t/8, t/4 kanye ne-3T/8
Akwaziwa ukuthi amagagasi aqondiswayo ahlukaniswa kanjani ne-antenna futhi ekugcineni akheke ukuze asakazeke endaweni ekhululekile. Singaqhathanisa amagagasi esikhala aqondiswayo nakhululekile namagagasi amanzi, okungabangelwa itshe eliwela emanzini athule noma ngezinye izindlela. Uma ukuphazamiseka emanzini kuqala, amagagasi amanzi ayakhiqizwa futhi aqale ukusakazeka ngaphandle. Ngisho noma ukuphazamiseka kuyeka, amagagasi awami kodwa ayaqhubeka nokusakazeka phambili. Uma ukuphazamiseka kuqhubeka, amagagasi amasha akhiqizwa njalo, futhi ukusakazeka kwala magagasi kusalele ngemuva kwamanye amagagasi.
Kunjalo nangamagagasi kagesi akhiqizwa ukuphazamiseka kukagesi. Uma ukuphazamiseka kokuqala kukagesi okuvela emthonjeni kungokwesikhathi esifushane, amagagasi kagesi akhiqizwayo asakazeka ngaphakathi komugqa wokudlulisela, bese engena ku-antenna, bese ekugcineni ekhipha njengamagagasi esikhala samahhala, yize ukuvusa kungasekho (njengamagagasi amanzi kanye nokuphazamiseka akudalile). Uma ukuphazamiseka kukagesi kuqhubeka, amagagasi kagesi akhona njalo futhi alandela eduze ngemuva kwawo ngesikhathi sokusabalala, njengoba kuboniswe ku-antenna ye-biconical eboniswe kuMfanekiso 5. Lapho amagagasi kagesi engaphakathi kwemigqa yokudlulisela kanye nama-antenna, ukuba khona kwawo kuhlobene nokuba khona kweshaja kagesi ngaphakathi komqhubi. Kodwa-ke, lapho amagagasi ekhishwa, akha iluphu evaliwe futhi akukho shaja yokugcina ukuba khona kwawo. Lokhu kusiholela esiphethweni sokuthi:
Ukuvusa insimu kudinga ukusheshisa kanye nokunciphisa ijubane lokushaja, kodwa ukugcinwa kwensimu akudingi ukusheshisa kanye nokunciphisa ijubane lokushaja.
Umfanekiso 5
3. Imisebe ye-Dipole
Sizama ukuchaza indlela imigqa yensimu kagesi ehlukana ngayo ne-antenna bese yakha amaza esikhala esikhululekile, bese sithatha i-antenna ye-dipole njengesibonelo. Nakuba kuyincazelo elula, futhi ivumela abantu ukuthi babone ngokwemvelo ukukhiqizwa kwamaza esikhala esikhululekile. Isithombe 6(a) sibonisa imigqa yensimu kagesi ekhiqizwa phakathi kwezingalo ezimbili ze-dipole lapho imigqa yensimu kagesi idlulela ngaphandle ngo-λ∕4 kwikota yokuqala yomjikelezo. Kulesi sibonelo, ake sicabange ukuthi inani lemigqa yensimu kagesi eyakhiwe lingu-3. Kwikota elandelayo yomjikelezo, imigqa emithathu yokuqala yensimu kagesi ihambisa enye i-λ∕4 (isamba esingu-λ∕2 kusukela endaweni yokuqala), futhi ubuningi beshaja kumqhubi buqala ukwehla. Kungabhekwa njengokwakhiwa ngokwethulwa kwamacala aphambene, okukhansela amacala kumqhubi ekupheleni kwengxenye yokuqala yomjikelezo. Imigqa yensimu kagesi ekhiqizwa ngamacala aphambene ingu-3 futhi ihambisa ibanga elingu-λ∕4, elimelelwa yimigqa enamachashazi kuMfanekiso 6(b).
Umphumela wokugcina ukuthi kunemigqa emithathu yensimu kagesi ehlayo ebangeni lokuqala le-λ∕4 kanye nenani elifanayo lemigqa yensimu kagesi ehlayo ebangeni lesibili le-λ∕4. Njengoba kungekho ukushaja okunetha ku-antenna, imigqa yensimu kagesi kumele iphoqeleke ukuthi ihlukane nomqhubi futhi ihlangane ndawonye ukuze yakhe iluphu evaliwe. Lokhu kuboniswe kuMfanekiso 6(c). Engxenyeni yesibili, kulandelwa inqubo efanayo ebonakalayo, kodwa qaphela ukuthi isiqondiso siphambene. Ngemva kwalokho, inqubo iyaphindwa futhi iyaqhubeka unomphela, yakha ukusatshalaliswa kwensimu kagesi okufana noMfanekiso 4.
Umfanekiso 6
Ukuze ufunde kabanzi ngama-antenna, sicela uvakashele:
Isikhathi sokuthunyelwe: Juni-20-2024
