Ibanga lokuxhumana elingafinyelelwa yisistimu yokuxhumana okungenazintambo linqunywa izici ezihlukahlukene ezifana namadivayisi ahlukahlukene akha uhlelo nendawo yokuxhumana. Ubudlelwano phakathi kwabo bungavezwa isibalo esilandelayo sebanga lokuxhumana.
Uma amandla okudlulisela edivayisi yokudlulisa yesistimu yokuxhumana kuyi-PT, inzuzo yothi lokudlulisela i-GT, kanti ubude begagasi obusebenzayo ngu-λ. Ukuzwela komamukeli wedivayisi eyamukelayo yi-PR, inzuzo eyamukelayo ye-antenna yi-GR, futhi ibanga phakathi kwezinti ezamukelayo nezizidluliselayo ngu-R, ngaphakathi kwebanga elibonakalayo nasendaweni ngaphandle kokuphazanyiswa nguzibuthe kagesi, ubuhlobo obulandelayo bukhona:
I-PT(dBm)-PR(dBm)+GT(dBi)+GR(dBi)=20log4pr(m)/l(m)+Lc(dB)+ L0(dB) Efomini, i-Lc iwukulahlekelwa kokufaka kwesiteshi esiyisisekelo esithumela i-antenna; I-L0 ukulahleka kwegagasi lomsakazo ngesikhathi sokusatshalaliswa.
Lapho uklama isistimu, kufanele kushiywe imaji eyanele entweni yokugcina, ukulahlekelwa kokusakazwa kwegagasi lomsakazo L0.
Ngokuvamile, umkhawulo we-10 kuya ku-15 dB uyadingeka lapho udlula emahlathini nezakhiwo zomphakathi; umkhawulo wama-30 kuya ku-35 dB uyadingeka uma udlula ezakhiweni zikakhonkolo eziqinisiwe.
Ku-800MH, 900ZMHz CDMA kanye namabhendi efrikhwensi ye-GSM, ngokuvamile kukholakala ukuthi izinga lokwamukela omakhalekhukhwini licishe libe ngu-104dBm, futhi isignali yangempela eyamukelwe kufanele okungenani ibe ngu-10dB ngaphezulu ukuze kuqinisekiswe isilinganiso esidingekayo sesignali-kuya-nomsindo. Eqinisweni, ukuze kugcinwe ukuxhumana okuhle, amandla atholiwe ngokuvamile abalwa njenge -70 dBm. Cabanga ukuthi isiteshi esiyisisekelo sinamapharamitha alandelayo:
Amandla okudlulisa yi-PT = 20W = 43dBm; amandla atholayo yi-PR = -70dBm;
Ukulahleka kwesiphakeli kungu-2.4dB (cishe i-60m feeder)
Iselula ethola i-antenna GR = 1.5dBi;
Ubude begagasi obusebenzayo λ = 33.333cm (okulingana nefrikhwensi f0 = 900MHz);
Isibalo sokuxhumana esingenhla sizoba:
43dBm-(-70dBm)+ GT(dBi)+1.5dBi=32dB+ 20logger(m) dB +2.4dB + ukulahlekelwa kokusakazwa L0
114.5dB+ GT(dBi) -34.4dB = 20logger(m)+ ukulahlekelwa kokusakazwa L0
80.1dB+ GT(dBi) = 20logger(m)+ ukulahlekelwa kokusakazwa L0
Uma inani elingakwesokunxele lefomula engenhla likhulu kunenani elingakwesokudla, okungukuthi:
GT(dBi) > 20log(m)-80.1dB+propagation ukulahlekelwa L0. Lapho ukungalingani kubambe, kungabhekwa ukuthi uhlelo lungagcina ukuxhumana okuhle.
Uma isiteshi esiyisisekelo sisebenzisa i-omnidirectional edlulisa i-antenna enenzuzo ye-GT=11dBi futhi ibanga phakathi kwezimpondo zokudlulisela nokwamukela lingu-R=1000m, isibalo sokuxhumana siqhubeka siba ngu-11dB>60-80.1dB+ukulahlekelwa kokusakazwa L0, okungukuthi, lapho ukulahlekelwa kokusakazwa kwe-L0<131 km kungagcinwa kahle phakathi kwebanga elingu-1.1 lokuxhumana.
Ngaphansi kwezimo ezifanayo zokulahlekelwa kokusabalalisa njengoba ngenhla, uma i-antenna yokudlulisela izuza i-GT = 17dBi, okungukuthi, ukwanda kwe-6dBi, ibanga lokuxhumana lingaphinda liphindwe kabili, okungukuthi, r = 2 amakhilomitha. Abanye banganqunywa ngendlela efanayo. Kodwa-ke, kufanele kuqashelwe ukuthi i-antenna yesiteshi esinenzuzo ye-GT ye-17dBi ingaba nembobo ye-beam emise okuka fan enobubanzi be-beam obungu-30°, 65° noma u-90°, njll., futhi ayikwazi ukugcina ukumbozwa kwe-omnidirectional.
Ukwengeza, uma i-antenna yokudlulisela izuza i-GT=11dBi ihlala ingashintshile ekubalweni okungenhla, kodwa indawo yokusabalalisa iyashintsha, ukulahlekelwa kokusakazwa L0=31.1dB-20dB=11.1dB, khona-ke ukulahlekelwa okuncishisiwe okungu-20dB kuzokwandisa ibanga lokuxhumana ngokuphindwe kashumi, okungukuthi, r=10 amakhilomitha. Itemu lokulahlekelwa kokusakazwa lihlobene nendawo ezungezile ye-electromagnetic. Ezindaweni zasemadolobheni, kunezakhiwo eziningi eziphakeme futhi ukulahlekelwa kokusatshalaliswa kukhulu. Ezindaweni zasemaphandleni ezisemaphandleni, izindlu zamapulazi ziphansi futhi zincane, futhi ukulahlekelwa kokusabalalisa kuncane. Ngakho-ke, noma ngabe izilungiselelo zesistimu yezokuxhumana zifana ncamashi, uhla lokuhlanganisa olusebenzayo luzohluka ngenxa yomehluko endaweni yokusetshenziswa.
Ngakho-ke, lapho ukhetha ama-omnidirectional, ama-antenna aqondisayo kanye namafomu e-antenna enenzuzo ephezulu noma ephansi, kuyadingeka ukuthi ucabangele ukusebenzisa izimpondo zesiteshi eziyisisekelo zezinhlobo ezahlukahlukene kanye nokucaciswa ngokwemibandela ethile yenethiwekhi yokuxhumana yeselula nendawo yohlelo lokusebenza.
Ukuze ufunde kabanzi ngama-antenna, sicela uvakashele:
Isikhathi sokuthumela: Jul-25-2025
