Oke bara uru na-agbakọ ike nnata nke antenna bụmpaghara dị irèma ọ bụirè oghere.Were ya na ife ụgbọ elu nwere otu polarization dị ka antenna nnata na-eme n'elu antenna.Ọzọkwa chere na ebili mmiri ahụ na-aga n'ihu antenna na ntụzịaka antenna nke radieshon kachasị (ntụziaka nke a ga-esi nweta ike kachasị).
Mgbe ahụirè oghereparamita na-akọwa oke ike ewepụtara n'ofe ụgbọ elu enyere.Kapbụrụ njupụta ike nke ikuku ụgbọ elu (na W/m^2).Ọ bụrụP_tna-anọchi anya ike (na Watts) na ọdụ antenna dị maka nnata antenna, wee:
N'ihi ya, mpaghara dị irè na-anọchi anya ole ike ewepụtara n'efegharị ụgbọ elu wee nyefee ya site na antenna.Mpaghara a na-ebute mfu ndị dị n'ime antenna (mfu ohmic, mfu dielectric, wdg).
A na-enye njikọ zuru oke maka oghere dị irè n'ihe gbasara uru antenna kacha elu (G) nke antenna ọ bụla:
Enwere ike tụọ oghere ma ọ bụ mpaghara dị irè na antennas n'ezie site na iji tụnyere antenna amaara nke nwere oghere dị irè enyere, ma ọ bụ site na ngụkọ site na iji uru atụtara na nha n'elu.
Oghere dị irè ga-abụ echiche bara uru maka ịgbakọ ike enwetara site na ife ụgbọ elu.Iji hụ nke a ka ọ na-eme, gaa na ngalaba na-esote na usoro nnyefe Friis.
Ndekọ nnyefe Friis
N'ibe a, anyị na-ewebata otu n'ime nha nhata kachasị na tiori antenna, nkeNtụnye Mbufe Friis.A na-eji nha nnyefe Friis iji gbakọọ ike enwetara site na otu antenna (yana uruG1), mgbe ebufere ya site na antenna ọzọ (na uruG2), kewapụrụ site n'ebe dị anyaR, ma na-arụ ọrụ ugboro olefma ọ bụ wavelength lambda.Ibe a kwesịrị ịgụ ugboro ole na ole ma ekwesịrị ịghọta ya nke ọma.
Mwepụta nke usoro nnyefe Friis
Iji malite mwepụta nke Friis Equation, tụlee antenna abụọ na ohere efu (enweghị ihe mgbochi dị nso) kewapụrụ site n'ebe dị anya.R:
Were ya na () Watts nke ike zuru oke na-ebunye na antenna mbufe.Maka oge a, chee na antenna na-ebufe bụ akụkụ ọ bụla, enweghị efu, yana na antenna nnata dị n'akụkụ dị anya nke antenna nnyefe.Mgbe ahụ ike njupụtap(na Watts kwa square mita) nke ụgbọ elu ebili mmiri mere na antenna nnata dị anyaRsitere na antenna mbufe bụ:
Ọgụgụ 1. Nyefee (Tx) na Nnata (Rx) Antennas kewapụrụR.
Ọ bụrụ na antenna na-ebufe nwere uru antenna na ntụzịaka nke antenna nnata nyere () , mgbe ahụ nha njupụta ike dị n'elu na-aghọ:
The uru okwu ihe na directionality na mfu nke ezigbo antenna.Were ya ugbu a na antenna nnata nwere oghere dị irè nyere site na().Mgbe ahụ a na-enye ike nke antenna ( ) enwetara site na:
Ebe ọ bụ na a na-egosipụtakwa oghere dị irè maka antenna ọ bụla dị ka:
Enwere ike dee ike enwetara dị ka:
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A maara nke a dị ka usoro nnyefe Friis.Ọ na-ejikọta mfu ụzọ oghere efu, uru antenna na ogologo ebili mmiri na ike nnata na ibufe.Nke a bụ otu n'ime nha nhata dị na tiori antenna, ma ekwesịrị icheta ya (yana mwepụta nke dị n'elu).
A na-enye ụdị ọzọ bara uru nke nha nnyefe Friis na nha nhata [2].Ebe ọ bụ na ogologo ogologo na ugboro f na-ejikọta ya na ọsọ nke ọkụ c (lee intro na ibe ugboro), anyị nwere usoro nnyefe Friis n'usoro nke ugboro:
Nhazi2
Nha nhata [2] na-egosi na ọtụtụ ike na-efunahụ n'ogo dị elu.Nke a bụ nsonaazụ dị mkpa sitere na nha nnyefe Friis.Nke a pụtara na maka antennas nwere uru a kapịrị ọnụ, nnyefe ike ga-adị elu na obere ugboro.A maara ọdịiche dị n'etiti ike natara na ike a na-ebufe dị ka ọnwụ ụzọ.Ekwuru n'ụzọ dị iche, Friis Transmission Equation na-ekwu na ọnwụ ụzọ dị elu maka ugboro ole dị elu.Mkpa nke nsonaazụ a sitere na Friis Transmission Formula enweghị ike ikwubiga ya ókè.Nke a bụ ya mere ekwentị mkpanaaka n'ozuzu na-arụ ọrụ na-erughị 2 GHz.Enwere ike ịnwe ụdịdị dị iche iche ugboro ugboro n'ogo dị elu, mana ọnwụ ụzọ jikọtara agaghị eme ka nnabata dị mma.Dị ka nsonaazụ ọzọ nke Friss Transmission Equation, were ya na a jụrụ gị gbasara antennas 60 GHz.N'ịrịba ama na ugboro a dị oke elu, ị nwere ike ikwu na ọnwụ ụzọ ga-adị elu maka nkwurịta okwu ogologo ogologo - na ị ziri ezi.N'ọtụtụ dị elu (60 GHz ka a na-akpọ mgbe ụfọdụ dị ka mpaghara mm (millimita wave)), ọnwụ ụzọ dị oke elu, yabụ naanị nkwurịta okwu na-aga n'ihu ga-ekwe omume.Nke a na-eme mgbe onye nata na nnyefe nọ n'otu ọnụ ụlọ, ma na-eche ibe ha ihu.Dị ka nkọwa ọzọ nke Friis Transmission Formula, ị chere na ndị na-ahụ maka ekwentị mkpanaaka nwere obi ụtọ maka otu LTE (4G) ọhụrụ, na-arụ ọrụ na 700MHz?Azịza ya bụ ee: nke a bụ ugboro dị ala karịa antennas na-arụ ọrụ na omenala, mana site na nha nha [2], anyị na-achọpụta na ọnwụ ụzọ ga-adịkwa ala.N'ihi ya, ha nwere ike "kpuchie ala ọzọ" site na ụdị ụdịdị a, yana onye isi Verizon Wireless kpọrọ ihe a "dị elu ụdịdị dị iche iche", kpọmkwem maka nke a.Ntụle akụkụ: N'aka nke ọzọ, ndị na-eme ekwentị ga-adaba na antenna nwere ogologo ogologo ogologo na ngwa kọmpat (obere ugboro = nnukwu wavelength), ya mere ọrụ onye nrụpụta antenna nwetara ntakịrị mgbagwoju anya!
N'ikpeazụ, ọ bụrụ na antennas ejikọtaghị ọnụ, ike a na-enweta n'elu nwere ike ịba ụba site na Polarization Loss Factor (PLF) iji kọwaa nke ọma maka ndakọrịta a.Enwere ike gbanwee nhata [2] dị n'elu iji mepụta usoro mgbasa ozi Friis n'ozuzu ya, nke gụnyere ndakọrịta polarization:
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Oge nzipu: Jan-08-2024
