Ibanga lokuxhumana elingafinyelelwa uhlelo lokuxhumana olungenantambo linqunywa yizici ezahlukahlukene ezifana namadivayisi ahlukahlukene akha uhlelo kanye nendawo yokuxhumana. Ubudlelwano phakathi kwawo bungabonakaliswa yi-equation elandelayo yebanga lokuxhumana.
Uma amandla okudlulisa edivayisi yokudlulisa yesistimu yokuxhumana eyi-PT, inzuzo ye-antenna yokudlulisa iyi-GT, kanti ubude be-wavelength yokusebenza buyi-λ. Ukuzwela kwesamukeli sedivayisi yokwamukela yi-PR, inzuzo ye-antenna yokwamukela yi-GR, kanti ibanga phakathi kwama-antenna amukelayo nadluliselayo lingu-R, ngaphakathi kwebanga elibonakalayo nasendaweni ezungezile ngaphandle kokuphazamiseka kwe-electromagnetic, kukhona ubudlelwano obulandelayo:
I-PT(dBm)-PR(dBm)+GT(dBi)+GR(dBi)=20log4pr(m)/l(m)+Lc(dB)+ L0(dB) Kule fomula, i-Lc iwukulahlekelwa kokufakwa kwe-feeder kwe-antenna edlulisela isiteshi sesisekelo; i-L0 iwukulahlekelwa kwamagagasi omsakazo ngesikhathi sokusabalala.
Lapho uklama uhlelo, kufanele kushiywe umkhawulo owanele wento yokugcina, ukulahlekelwa kokusabalala kwamagagasi omsakazo L0.
Ngokuvamile, kudingeka umkhawulo ongu-10 kuya ku-15 dB uma kudlula emahlathini nasezindlini zomphakathi; umkhawulo ongu-30 kuya ku-35 dB uyadingeka uma kudlula ezakhiweni zekhonkrithi eziqinisiwe.
Kuma-frequency band angu-800MH, 900ZMHz CDMA kanye ne-GSM, ngokuvamile kukholelwa ukuthi izinga lomkhawulo wokwamukela lamafoni aphathekayo licishe libe yi--104dBm, futhi isignali yangempela eyamukelwe kufanele okungenani ibe ngaphezulu kwe-10dB ukuqinisekisa isilinganiso esidingekayo sesignali-kuya-kumsindo. Eqinisweni, ukuze kugcinwe ukuxhumana okuhle, amandla amukelwe avame ukubalwa njengo--70 dBm. Cabanga ukuthi isiteshi esiyisisekelo sinemingcele elandelayo:
Amandla okudlulisa yi-PT = 20W = 43dBm; amandla okwamukela yi-PR = -70dBm;
Ukulahlekelwa kwe-feeder kungu-2.4dB (cishe i-feeder engu-60m)
Ukwanda kwe-antenna ethola ifoni ephathekayo GR = 1.5dBi;
Ubude besikhathi obusebenzayo λ = 33.333cm (okulingana nemvamisa f0 = 900MHz);
I-equation yokuxhumana engenhla izoba:
43dBm-(-70dBm)+ GT(dBi)+1.5dBi=32dB+ 20logr(m) dB +2.4dB + ukulahlekelwa kokusabalala L0
114.5dB+ GT(dBi) -34.4dB = 20logr(m)+ ukulahlekelwa kokusabalala L0
80.1dB+ GT(dBi) = 20logr(m)+ ukulahlekelwa kokusabalala L0
Uma inani elingakwesokunxele lefomula engenhla likhulu kunenani elingakwesokudla, okungukuthi:
I-GT(dBi) > 20logr(m)-80.1dB+ukulahlekelwa kokusabalala L0. Uma ukungalingani kuqhubeka, kungacatshangwa ukuthi uhlelo lungalondoloza ukuxhumana okuhle.
Uma isiteshi esiyisisekelo sisebenzisa i-antenna yokudlulisa eqondisa yonke indawo enokwanda kwe-GT=11dBi futhi ibanga eliphakathi kwama-antenna okudlulisa nokwamukela lingu-R=1000m, i-equation yokuxhumana iba yi-11dB>60-80.1dB+ukulahlekelwa kokusabalala L0, okungukuthi, lapho ukulahlekelwa kokusabalala L0<31.1dB, ukuxhumana okuhle kungagcinwa ngaphakathi kwebanga elingu-1 km.
Ngaphansi kwezimo ezifanayo zokulahlekelwa kokusabalala njengoba kushiwo ngenhla, uma i-antenna ethumelayo ithola i-GT = 17dBi, okungukuthi, ukwanda kwe-6dBi, ibanga lokuxhumana lingaphindeka kabili, okungukuthi, i-r = amakhilomitha ama-2. Amanye angatholakala ngendlela efanayo. Kodwa-ke, kufanele kuqashelwe ukuthi i-antenna yesiteshi esiyisisekelo ene-GT ethola i-17dBi ingaba nombobo womshanelo ofana nowefeni kuphela onobubanzi bomshanelo obungu-30°, 65° noma 90°, njll., futhi ayikwazi ukugcina umbobo oqondene nendawo yonke.
Ngaphezu kwalokho, uma inzuzo ye-antenna yokudlulisa i-GT=11dBi ingashintshi ekubalweni okungenhla, kodwa indawo yokusabalala ishintsha, ukulahlekelwa kokusabalala L0=31.1dB-20dB=11.1dB, khona-ke ukulahlekelwa kokusabalala okungu-20dB okuncishisiwe kuzokwandisa ibanga lokuxhumana ngokuphindwe kayishumi, okungukuthi, r=10 amakhilomitha. Isikhathi sokulahlekelwa kokusabalala sihlobene nendawo ezungezile ye-electromagnetic. Ezindaweni zasemadolobheni, kunezakhiwo eziningi eziphakeme futhi ukulahlekelwa kokusabalala kukhulu. Ezindaweni zasemaphandleni zasemadolobheni, izindlu zasemapulazini ziphansi futhi zimbalwa, kanti ukulahlekelwa kokusabalala kuncane. Ngakho-ke, noma ngabe izilungiselelo zesistimu yokuxhumana zifana ncamashi, ububanzi bokumboza obusebenzayo buzohluka ngenxa yomehluko endaweni yokusetshenziswa.
Ngakho-ke, lapho ukhetha ama-antenna aqondisa yonke indawo, aqondisa yonke indawo kanye namafomu e-antenna athola inzuzo ephezulu noma ethola inzuzo ephansi, kubalulekile ukucabangela ukusebenzisa ama-antenna asesiteshini sesisekelo ezinhlobo ezahlukene kanye nezincazelo ngokuya ngezimo ezithile zenethiwekhi yokuxhumana yeselula kanye nendawo yohlelo lokusebenza.
Ukuze ufunde kabanzi ngama-antenna, sicela uvakashele:
Isikhathi sokuthunyelwe: Julayi-25-2025
