Gawo lothandiza powerengera mphamvu yolandirira ya antenna ndimalo ogwira ntchitokapenakutsegula bwinoTangoganizani kuti mafunde a ndege omwe ali ndi polarization yofanana ndi antenna yolandira amachitika pa antenna. Komanso, tangoganizani kuti mafundewo akupita ku antenna motsatira njira ya antenna yomwe ili ndi mphamvu zambiri (komwe mphamvu zambiri zingalandiridwe).

Kenakokutsegula bwinoGawo limafotokoza kuchuluka kwa mphamvu zomwe zimagwidwa kuchokera ku mafunde a ndege inayake.pkhalani ndi mphamvu ya mafunde a ndege (mu W/m^2). NgatiP_timayimira mphamvu (mu Watts) pa ma terminal a antenna omwe amapezeka kwa wolandila antenna, kenako:

Choncho, malo ogwira ntchito amangoyimira kuchuluka kwa mphamvu zomwe zimagwidwa kuchokera ku mafunde a ndege ndikuperekedwa ndi antenna. Malo awa amatanthauza kutayika kwa antenna (kutayika kwa ohmic, kutayika kwa dielectric, ndi zina zotero).

Chiyanjano chachikulu cha kutsegula bwino kwa antenna potengera kuchuluka kwa antenna (G) ya antenna iliyonse chimaperekedwa ndi:

Malo otseguka bwino kapena malo otseguka bwino akhoza kuyezedwa pa ma antenna enieni poyerekeza ndi antenna yodziwika bwino yokhala ndi malo otseguka bwino, kapena powerengera pogwiritsa ntchito phindu loyezedwa ndi equation yomwe ili pamwambapa.

Kutsegula bwino kwa mphamvu kudzakhala lingaliro lothandiza powerengera mphamvu yolandiridwa kuchokera ku mafunde a ndege. Kuti muwone izi zikugwira ntchito, pitani ku gawo lotsatira la fomula ya Friis transmission.

The Friis Transmission Equation

Patsamba lino, tikuyambitsa chimodzi mwa ma equation ofunikira kwambiri mu chiphunzitso cha antenna,Friis Transmission EquationFriis Transmission Equation imagwiritsidwa ntchito kuwerengera mphamvu yolandiridwa kuchokera ku antenna imodzi (ndi phinduG1), ikatumizidwa kuchokera ku antenna ina (ndi phinduG2), yolekanitsidwa ndi mtundaR, ndi kugwira ntchito pafupipafupifkapena kutalika kwa nthawi ya lambda. Tsamba ili ndi loyenera kuwerengedwa kangapo ndipo liyenera kumvedwa bwino.

Kuchokera kwa Friis Transmission Formula

Kuti muyambe kupeza Friis Equation, ganizirani ma antenna awiri omwe ali pamalo omasuka (opanda zopinga pafupi) olekanitsidwa ndi mtunda.R:

Tangoganizani kuti （）Ma Watts a mphamvu yonse amaperekedwa ku antenna yotumizira. Pakadali pano, tangoganizani kuti antenna yotumizira ndi yolunjika mbali zonse, yopanda kutayika, ndipo antenna yolandira ili kutali ndi antenna yotumizira. Kenako mphamvu yamagetsi ndi yocheperako.p(mu ma Watts pa mita imodzi ya sikweya) ya ngozi ya mafunde a ndege pa antenna yolandila mtundaRkuchokera ku antenna yotumizira imaperekedwa ndi:

Chithunzi 1. Ma Antena otumiza (Tx) ndi olandila (Rx) olekanitsidwa ndiR.

Ngati antenna yotumizira ili ndi antenna yowonjezera mbali ya antenna yolandira yomwe yaperekedwa ndi (） ), ndiye kuti equation ya mphamvu yamagetsi pamwambapa idzakhala:

Mphamvu ya antenna yeniyeni imayang'ana mbali ndi kutayika kwa antenna yeniyeni. Tangoganizani kuti antenna yolandirayo ili ndi malo otseguka bwino omwe amaperekedwa ndi()Kenako mphamvu yomwe antenna iyi ( ) imalandira imaperekedwa ndi:

Popeza kutsegula kogwira mtima kwa antenna iliyonse kungafotokozedwe motere:

Mphamvu yolandirira yomwe yapezeka ikhoza kulembedwa motere:

Chiyerekezo 1

Izi zimadziwika kuti Friis Transmission Formula. Zimagwirizanitsa kutayika kwa njira yaulere, phindu la antenna ndi kutalika kwa mafunde ndi mphamvu zolandiridwa ndi zotumizira. Ichi ndi chimodzi mwa ma equation ofunikira mu chiphunzitso cha antenna, ndipo chiyenera kukumbukiridwa (komanso zomwe zachokera pamwambapa).

Mtundu wina wothandiza wa Friis Transmission Equation waperekedwa mu Equation [2]. Popeza kutalika kwa nthawi ndi pafupipafupi f zimagwirizana ndi liwiro la kuwala c (onani tsamba loyamba la pafupipafupi), tili ndi Friis Transmission Formula pankhani ya pafupipafupi:

Chiyerekezo 2

Equation [2] ikuwonetsa kuti mphamvu zambiri zimatayika pama frequency apamwamba. Ichi ndi zotsatira zazikulu za Friis Transmission Equation. Izi zikutanthauza kuti pa ma antenna omwe ali ndi phindu linalake, kusamutsa mphamvu kudzakhala kwakukulu pama frequency otsika. Kusiyana pakati pa mphamvu yolandiridwa ndi mphamvu yotumizidwa kumadziwika kuti path loss. Ponena mwanjira ina, Friis Transmission Equation imati kutayika kwa njira kumakhala kwakukulu pama frequency apamwamba. Kufunika kwa zotsatirazi kuchokera ku Friis Transmission Formula sikunganyalanyazidwe. Ichi ndichifukwa chake mafoni am'manja nthawi zambiri amagwira ntchito pamunsi pa 2 GHz. Pakhoza kukhala ma frequency ambiri omwe amapezeka pama frequency apamwamba, koma kutayika kwa njira komwe kumagwirizanitsidwa sikungathandize kulandira bwino. Monga zotsatira zina za Friss Transmission Equation, tiyerekeze kuti mwafunsidwa za ma antenna a 60 GHz. Podziwa kuti frequency iyi ndi yayikulu kwambiri, munganene kuti kutayika kwa njira kudzakhala kwakukulu kwambiri kuti mulumikizane patali - ndipo ndinu wolondola kwathunthu. Pa ma frequency apamwamba kwambiri (60 GHz nthawi zina amatchedwa mm (millimeter wave) region), kutayika kwa njira kumakhala kwakukulu kwambiri, kotero kulumikizana kwa mfundo ndi mfundo kokha ndikotheka. Izi zimachitika pamene wolandila ndi wotumiza ali m'chipinda chimodzi, ndipo akuyang'anizana. Monga njira ina yotsatirira Friis Transmission Formula, kodi mukuganiza kuti ogwira ntchito pafoni akusangalala ndi gulu latsopano la LTE (4G), lomwe limagwira ntchito pa 700MHz? Yankho ndi inde: iyi ndi nthawi yocheperako kuposa ma antenna omwe nthawi zambiri amagwira ntchito, koma kuchokera ku Equation [2], tikuwona kuti kutayika kwa njira kudzakhala kotsika. Chifukwa chake, amatha "kuphimba malo ambiri" ndi ma frequency spectrum awa, ndipo Verizon Wireless executive posachedwapa adatcha izi "high quality spectrum", chifukwa chake. Chidziwitso Cham'mbali: Kumbali ina, opanga mafoni ayenera kuyika antenna yokhala ndi mafunde akuluakulu mu chipangizo chocheperako (mafunde otsika = mafunde akuluakulu), kotero ntchito ya wopanga ma antenna inakhala yovuta pang'ono!

Pomaliza, ngati ma antenna sakugwirizana ndi polarization, mphamvu yolandiridwa pamwambapa ikhoza kuchulukitsidwa ndi Polarization Loss Factor (PLF) kuti iwerengere bwino kusagwirizana kumeneku. Equation [2] pamwambapa ikhoza kusinthidwa kuti ipange generalized Friis Transmission Formula, yomwe ikuphatikizapo kusagwirizana kwa polarization: