isithombe 1
1. Ukusebenza kahle kwe-beam
Enye ipharamitha evamile yokuhlola ikhwalithi yama-antenna okudlulisa nokwamukela ukusebenza kahle kwe-beam. Ku-antenna ene-lobe eyinhloko ohlangothini lwe-z-axis njengoba kuboniswe kuMfanekiso 1, ukusebenza kahle kwe-beam (BE) kuchazwa kanje:
Kuyisilinganiso samandla adlulisiwe noma atholiwe ngaphakathi kwe-engeli yekhoni θ1 kumandla aphelele adlulisiwe noma atholiwe yi-antenna. Ifomula engenhla ingabhalwa kanje:
Uma i-engeli lapho iphuzu lokuqala lika-zero noma inani eliphansi livela khona likhethwa njengo-θ1, ukusebenza kahle kwe-beam kumelela isilinganiso samandla ku-lobe eyinhloko namandla aphelele. Ezinhlelweni ezifana ne-metrology, i-astronomy, kanye ne-radar, i-antenna idinga ukuba nokusebenza kahle kwe-beam okuphezulu kakhulu. Ngokuvamile kudingeka okungaphezu kuka-90%, futhi amandla atholwa yi-lobe eseceleni kumele abe mancane ngangokunokwenzeka.
2. Ububanzi be-bandwidth
I-bandwidth ye-antenna ichazwa ngokuthi "ububanzi bemvamisa lapho ukusebenza kwezici ezithile ze-antenna kuhlangabezana khona nezindinganiso ezithile". I-bandwidth ingabhekwa njengobubanzi bemvamisa kuzo zombili izinhlangothi zemvamisa ephakathi (ngokuvamile okubhekisela kumvamisa we-resonant) lapho izici ze-antenna (njenge-input impedance, iphethini yokuqondisa, i-beamwidth, i-polarization, izinga le-sidelobe, i-gain, i-beam pointing, ukusebenza kahle kwemisebe) zingaphakathi kobubanzi obamukelekayo ngemva kokuqhathanisa inani lemvamisa ephakathi.
． Kuma-antenna e-broadband, i-bandwidth ivame ukuvezwa njengesilinganiso samaza aphezulu naphansi okusebenza okwamukelekayo. Isibonelo, i-bandwidth engu-10:1 isho ukuthi imvamisa ephezulu iphindwe kayishumi kunemvamisa ephansi.
． Kuma-antenna e-narrowband, i-bandwidth ivezwa njengephesenti lomehluko wemvamisa enanini eliphakathi. Isibonelo, i-bandwidth engu-5% isho ukuthi ububanzi bemvamisa obamukelekayo bungu-5% wemvamisa ephakathi.
Ngenxa yokuthi izici ze-antenna (i-input impedance, iphethini yokuqondisa, i-gain, i-polarization, njll.) ziyahlukahluka ngokwemvamisa, izici ze-bandwidth azihlukile. Ngokuvamile izinguquko kuphethini yokuqondisa kanye ne-input impedance zihlukile. Ngakho-ke, i-directional pattern bandwidth kanye ne-impedance bandwidth ziyadingeka ukuze kugcizelelwe lo mehluko. I-directional pattern bandwidth ihlobene ne-gain, izinga le-sidelobe, i-beadwidth, i-polarization kanye ne-beam direction, kuyilapho i-input impedance kanye nokusebenza kahle kwemisebe kuhlobene ne-impedance bandwidth. I-bandwidth ivame ukushiwo ngokwe-beadwidth, amazinga e-sidelobe, kanye nezici zephethini.
Ingxoxo engenhla icabanga ukuthi ubukhulu benethiwekhi yokuxhuma (i-transformer, i-counterpoise, njll.) kanye/noma i-antenna abushintshi nganoma iyiphi indlela njengoba imvamisa ishintsha. Uma ubukhulu obubalulekile be-antenna kanye/noma inethiwekhi yokuxhuma bungalungiswa kahle njengoba imvamisa ishintsha, i-bandwidth ye-antenna ye-narrowband ingandiswa. Nakuba lokhu kungewona umsebenzi olula ngokuvamile, kunezinhlelo zokusebenza lapho kungafezeka khona. Isibonelo esivame kakhulu yi-antenna yomsakazo emsakazweni wemoto, evame ukuba nobude obulungisekayo obungasetshenziswa ukulungisa i-antenna ukuze yamukelwe kangcono.
Ukuze ufunde kabanzi ngama-antenna, sicela uvakashele:
Isikhathi sokuthunyelwe: Julayi-12-2024
