I-antenna emfutshane ye-dipole yenye yeemodeli ezisisiseko ezisetyenziswa kwithiyori ye-antenna. Yi-antenna elula yocingo oluthe ngqo enobude obupheleleyo obuncinci kakhulu kunobude bomsinga wesignali yokusebenza. Nangona isakhiwo sibonakala silula kakhulu, i-dipole emfutshane yimodeli ebalulekileyo yokuqonda ukusasazwa kwangoku, ukuziphatha kwemitha, ukuthintelwa kwe-antenna, kunye nolwalamano phakathi kobukhulu be-antenna kunye nobude bomsinga.
Kwinjineli ye-antenna, i-dipole idla ngokuthathwa njenge "mfutshane" xa ubude bayo bubonke bungaphantsi kwesinye kwishumi sobude bomda:
L < \frac{\lambda}{10}
Apha, i-(L) imele ubude bomqhubi we-dipole, kwaye i-(\lambda) imele ubude be-wavelength kwi-frequency yokusebenza. Le nkcazo isekelwe kubude bombane endaweni yoluhlu lwe-frequency oluzinzileyo. Ngamanye amazwi, i-dipole emfutshane inokuvela ngokwethiyori kwiibhendi ze-frequency ezahlukeneyo logama nje ubude bayo bomzimba buhlala buncinci kakhulu kunobude be-wavelength.
Ngenxa yokuba i-antenna imfutshane ngombane, ukusasazwa kwamandla ombane ecaleni kwe-conductor kwahlukile kokwe-half-wave dipole. Kwi-short dipole esebenzayo, amandla ombane adla ngokuba maninzi kufutshane nendawo yokuphakelwa kwaye anciphe ukuya eziphelweni ze-conductor. Ekubeni ubude be-conductor bufutshane kakhulu kunobude be-wavelength, i-antenna ayisebenzisi ubukhulu bayo bomzimba ngokufanelekileyo kwi-radiation. Ngenxa yoko, ii-short dipoles zihlala zinokumelana okuphantsi kwe-radiation kunye nokusebenza okuphantsi kwe-radiation, ingakumbi xa kucingelwa ukulahleka kwe-conductor kunye nokulahleka kokuhambelana.
Imodeli yethiyori enxulumeneyo yi-infinitesimal dipole. I-infinitesimal dipole yi-antenna eqikelelweyo enobude obuncinci kakhulu kunobude bomda. Idla ngokubonakaliswa ngolu hlobo:
[\Delta l \ll \lambda]
Kwezinye iimodeli ze-antenna ezilula, i-infinitesimal dipole inokuthiwa inosasazo lwamandla olufanayo. Oku kuyenza ibe luncedo kuhlalutyo lwethiyori, nangona ingelulo ulwakhiwo lwe-antenna olusebenzayo ngokwalo. Iinjineli zihlala zisebenzisa i-infinitesimal dipole njengebhloko yokwakha ukuqonda iingxaki zemitha ye-antenna ezintsonkothileyo.
Kwizakhiwo ze-antenna zokwenyani, iipleyiti zokulayisha ezikwaziyo ukuthwala okanye izinto zokulayisha ngaphezulu zingasetyenziselwa ukuphucula usasazo lwangoku okanye ukunciphisa ubungakanani bomzimba benkqubo ye-antenna. Ezi zakhiwo zokulayisha zinokunceda ukwenza i-antenna emfutshane ngombane isebenziseke ngakumbi, kodwa azitshintshi inyani esisiseko yokuba i-dipole emfutshane ayisebenzi kakuhle kune-antenna evakalayo efana ne-dipole yesiqingatha samaza.
Ipateni yemitha ye-dipole emfutshane ifana nqwa ne-dipole yesiqingatha samaza. Ukuba i-dipole ibekwe ngokuthe nkqo, ipateni yayo yemitha iphantse ibe yi-omnidirectional kwi-horizontal plane. Kwimbono enamacala amabini, ipateni idla ngokuchazwa njengemilo yesibalo-esibhozo, apho imitha ephezulu ihambelana ngqo ne-axis ye-antenna kunye nemitha encinci ecaleni kwe-axis ye-antenna.
Ii-antenna ze-dipole ezimfutshane zihlala zixoxwa kwiinkqubo zokufumana i-frequency ephantsi kunye ne-medium-frequency, apho ubude be-wavelength bude kakhulu kwaye i-antenna eguquguqukayo ngokomzimba inokuba nkulu kakhulu ukuba ingakhiwa. Kwezi meko, i-dipole emfutshane inika isakhiwo sokwamkela esincinci, nangona ukuhambelana kwe-impedance kunye nokusebenza kakuhle kufuneka kuqwalaselwe ngononophelo.
Ngokwembono yobunjineli, i-short dipole ingaphezulu nje kohlobo lwe-antenna olulula. Inceda ekuchazeni ukuba kutheni ubude be-antenna bubalulekile, indlela ukusasazwa kwangoku okuchaphazela ngayo imitha, kunye nokuba kutheni ii-antenna ezincinci zombane zihlala zifuna iinethiwekhi ezifanayo okanye iindlela zokulayisha. Kwiinjineli ze-RF kunye ne-microwave, ukuqonda i-short dipole kunika isiseko esiluncedo sokufunda ii-antenna ezisebenzayo, ii-antenna ezincinci zombane, ii-antenna zokulinganisa, kunye neenkqubo ze-antenna eziphambili.
Ukuze ufunde okungakumbi ngee-antenna, nceda undwendwele:
Ixesha leposi: Juni-26-2026
