I-Directivity iyipharamitha ye-antenna eyisisekelo. Lesi isilinganiso sokuthi injani iphethini yemisebe ye-antenna eqondisayo. I-antenna ekhanya ngokulinganayo kuzo zonke izinhlangothi izoba nokuqondisa okulingana no-1. (Lokhu kulingana noziro decibel -0 dB).
Umsebenzi wezixhumanisi eziyindilinga ungabhalwa njengephethini yemisebe evamile:
[Isibalo 1]
Iphethini yemisebe evamile inomumo ofanayo nephethini yemisebe yasekuqaleni. Iphethini yemisebe evamile yehliswa ngobukhulu kangangokuthi inani eliphakeme lephethini yemisebe lilingana no-1. (Elikhulu isibalo [1] sokuthi "F"). Ngokwezibalo, ifomula yokuqondisa (uhlobo "D") ibhalwe kanje:
Lokhu kungase kubonakale njenge-equation yokuqondisa eyinkimbinkimbi. Nokho, amaphethini emisebe yama-molecule anenani elikhulu kakhulu. Idinomineyitha imelela isilinganiso samandla asakazwa kuzo zonke izinhlangothi. I-equation ibe isilinganisela samandla omsebe aphezulu ahlukaniswa ngesilinganiso. Lokhu kunikeza ukuqondisa kwe-antenna.
Ipharadigm yokuqondisa
Njengesibonelo, cabanga ngezibalo ezimbili ezilandelayo zephethini yemisebe yezimpondo ezimbili.
I-Antenna 1
I-Antenna 2
Lawa maphethini emisebe ahlelwe kuMfanekiso 1. Sicela uqaphele ukuthi imodi yemisebe iwumsebenzi we-polar angle theta(θ)Iphethini yemisebe ayiwona umsebenzi we-azimuth. (Iphethini yemisebe ye-azimuthal ihlala ingashintshiwe). Iphethini yemisebe ye-antenna yokuqala ayiqondise kancane, bese kuba iphethini yemisebe yothi lwesibili. Ngakho-ke, silindele ukuthi ukuqondisa kube phansi ku-antenna yokuqala.
umfanekiso 1. Umdwebo wephethini yokukhishwa kwemisebe yothi. Inokuqondisa okuphezulu?
Sisebenzisa ifomula [1], singabala ukuthi uthi lunokuqondisa okuphakeme. Ukuze uhlole ukuqonda kwakho, cabanga ngoMfanekiso 1 nokuthi kuyini ukuqondiswa. Bese unquma ukuthi iyiphi i-antenna enokuqondisa okuphezulu ngaphandle kokusebenzisa noma yiziphi izibalo.
Imiphumela yokubala eyisiqondiso, sebenzisa ifomula [1]:
Isibalo se-antenna 1 eqondile, 1.273 (1.05 dB).
Isibalo se-antenna 2 eqondile, 2.707 (4.32 dB).
Ukunyuswa kokuqondisa kusho i-antenna egxile kakhulu noma eqondisayo. Lokhu kusho ukuthi i-antenna eyamukela-2 inamandla aqondisayo okuphakama kwayo izikhathi ezingu-2.707 kune-omnidirectional antenna. I-antenna 1 izothola izikhathi ezingu-1.273 amandla we-omnidirectional antenna. Ama-antenna e-Omnidirectional asetshenziswa njengereferensi evamile nakuba zingekho izimpondo ze-isotropic ezikhona.
Izinti zocingo kufanele zibe nokuqondisa okuphansi ngoba amasignali angavela kunoma iyiphi indlela. Ngokuphambene, izitsha zesathelayithi zinokuqondiswa okuphezulu. Isitsha sesathelayithi samukela amasiginali asuka endaweni engaguquki. Isibonelo, uma uthola isitsha se-TV yesathelayithi, inkampani izokutshela ukuthi usikhomba kuphi futhi isidlo sizothola isignali oyifunayo.
Sizophetha ngohlu lwezinhlobo ze-antenna kanye nokuqondisa kwazo. Lokhu kuzokunikeza umbono wokuthi yikuphi ukuqondiswa okuvamile.
Uhlobo lwe-antenna Ukuqondisa okujwayelekile Ukuqondisa okujwayelekile [decibel] (dB)
I-antenna emfushane ye-dipole 1.5 1.76
I-antenna ye-Half-wave ye-dipole 1.64 2.15
Isiqephu (i-microstrip antenna) 3.2-6.3 5-8
Uphondo lwe-antenna 10-100 10-20
I-antenna yesitsha 10-10,000 10-40
Njengoba idatha engenhla ibonisa ukuqondisa kwe-antenna kuyahluka kakhulu. Ngakho-ke, kubalulekile ukuqonda ukuqondisa lapho ukhetha i-antenna yohlelo lwakho lokusebenza oluthile. Uma udinga ukuthumela noma ukwamukela amandla kusuka eziqondisweni eziningi ohlangothini olulodwa kuzomele udizayine uthi olunokuqondisa okuphansi. Izibonelo zezinhlelo zokusebenza zama-antenna okuqondisa okuphansi zifaka imisakazo yemoto, omakhalekhukhwini, nokufinyelela ku-inthanethi okungenantambo kwekhompyutha. Ngokuphambene, uma wenza inzwa yokude noma ukudlulisa amandla okuqondiwe, kuzodingeka i-antenna eqonde kakhulu. Ama-antenna aqondiswe kakhulu azokhulisa ukudluliswa kwamandla esuka endaweni oyifunayo futhi anciphise amasignali asuka ezindleleni ezingafuneki.
Ake sithi sifuna i-antenna ephansi yokuqondisa. Sikwenza kanjani lokhu?
Umthetho ojwayelekile wethiyori ye-antenna ukuthi udinga i-antenna encane kagesi ukuze ukhiqize ukuqondisa okuphansi. Okusho ukuthi, uma usebenzisa i-antenna enosayizi ophelele we-0.25 - 0.5 wavelength, uzonciphisa ukuqondisa. Ama-antenna e-dipole ayingxenye yegagasi noma izimpondo ze-wavelength eziyisigamu ngokuvamile zinokuqondiswa okungaphansi kuka-3 dB. Lokhu kuphansi njengokuqondisa ongakuthola ekusebenzeni.
Ekugcineni, asikwazi ukwenza izinti zibe zincane kunekota ye-wavelength ngaphandle kokunciphisa ukusebenza kahle kwe-antenna kanye nomkhawulokudonsa we-antenna. Ukusebenza kahle kwe-antenna kanye nomkhawulokudonsa we-antenna kuzoxoxwa ngakho ezahlukweni ezizayo.
Ukuze uthole i-antenna enokuqondisa okuphezulu, sizodinga ama-antenna amasayizi amaningi we-wavelength. Okufana nama-antenna esitsha sesathelayithi nezimpondo zophondo zinokuqondiswa okuphezulu. Ngokwengxenye lokhu kungenxa yokuthi maningi amaza ubude.
Kungani kunjalo? Ekugcineni, isizathu sihlobene nezakhiwo ze-Fourier transform. Uma uthatha i-Fourier transform ye-pulse emfushane, uthola i-spectrum ebanzi. Lesi sifaniso asikho ekunqumeni iphethini yemisebe yothi. Iphethini yemisebe ingacatshangwa njengoguquko lweFourier lokusatshalaliswa kwamandla amanje noma amandla kagesi eduze kothi. Ngakho-ke, izimpondo ezincane zinamaphethini emisebe abanzi (kanye nokuqondisa okuphansi). Ama-antenna ane-voltage enkulu efanayo noma ukusatshalaliswa kwamanje Amaphethini aqondisayo kakhulu (nokuqondisa okuphezulu).
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Isikhathi sokuthumela: Nov-07-2023
