umfanekiso 1
1. Ukusebenza kakuhle kwebeam
Enye iparameter eqhelekileyo yokuvavanya umgangatho wokuhambisa kunye nokufumana i-eriyali kukusebenza kakuhle kwe-beam. Kwi-eriyali ene-lobe ephambili kwicala le-z-axis njengoko kubonisiwe kuMfanekiso 1, ukusebenza kakuhle kwe-beam (BE) kuchazwa ngolu hlobo:
Lumlinganiselo wamandla athunyelweyo okanye afunyenweyo ngaphakathi kwe-engile yekhowuni θ1 kumandla ewonke athunyelwe okanye amkelwe yi-eriyali. Le fomula ingasentla ingabhalwa ngolu hlobo:
Ukuba i-engile apho iphoyinti yokuqala ye-zero okanye ixabiso elincinci libonakala likhethwe njenge-θ1, ukusebenza kwe-beam kubonisa umlinganiselo wamandla kwi-lobe engundoqo kumandla onke. Kwizicelo ezinje nge-metrology, i-astronomy, kunye ne-radar, i-eriyali kufuneka ibe nokusebenza kakuhle kwe-antenna. Ngokuqhelekileyo ngaphezu kwe-90% efunekayo, kwaye amandla afunyenwe yi-lobe yecala kufuneka abe mancinci kangangoko.
2. Ubungakanani boluhlu
I-bandwidth ye-eriyali ichazwa "njengoluhlu lwamaza okuphindaphinda apho ukusebenza kweempawu ezithile ze-eriyali kuhlangabezana nemigangatho ethile". I-bandwidth inokuthathwa njengoluhlu lwamafrikhwensi kumacala omabini eziko lokuphindaphinda (ngokukodwa ngokubhekisele kwi-resonant frequency) apho iimpawu ze-antenna (ezifana ne-impedance yegalelo, ipateni yolwalathiso, i-beamidth, i-polarization, inqanaba le-sidelobe, inzuzo, ukukhomba i-beam, i-radiation ukusebenza kakuhle) ziphakathi koluhlu olwamkelekileyo emva kokuthelekisa ixabiso lefrikhwensi yeziko.
. Kwii-antenna ze-broadband, i-bandwidth idla ngokuchazwa njengomlinganiselo we-frequency ephezulu kunye nesezantsi yokusebenza okwamkelekileyo. Ngokomzekelo, i-bandwidth ye-10: i-1 ithetha ukuba i-frequency ephezulu ngamaxesha angama-10 aphantsi.
. Kwii-antenna ze-narrowband, i-bandwidth ibonakaliswe njengepesenti ye-frequency umahluko kwixabiso leziko. Ngokomzekelo, i-5% ye-bandwidth ithetha ukuba uluhlu lwamafrikhwensi olwamkelekileyo luyi-5% ye-frequency center.
Ngenxa yokuba iimpawu ze-antenna (i-impedance ye-input, iphethini yolwalathiso, inzuzo, i-polarization, njl.) iyahluka ngokuphindaphindiweyo, iimpawu ze-bandwidth azifani. Ngokuqhelekileyo utshintsho kwipatheni yesalathiso kunye ne-impedance yegalelo iyahluka. Ke ngoko, i-bandwidth yendlela yolwalathiso kunye ne-impedance bandwidth iyafuneka ukugxininisa lo mahluko. I-bandwidth yepateni ye-directional ihambelana nenzuzo, inqanaba le-sidelobe, i-beamidth, i-polarization kunye ne-beam direction ye-beam, ngelixa i-impedance yegalelo kunye nokusebenza kwe-radiation kuhambelana ne-impedance bandwidth. I-Bandwidth idla ngokuchazwa ngokubhekiselele kwi-beamwidth, amanqanaba e-sidelobe, kunye neempawu zepateni.
Le ngxoxo ingentla ithatha ukuba imilinganiselo yenethiwekhi yokudibanisa (i-transformer, i-counterpoise, njl.) kunye / okanye i-eriyali ayitshintshi nangayiphi na indlela njengoko i-frequency itshintsha. Ukuba imilinganiselo ebalulekileyo ye-antenna kunye / okanye inethiwekhi yokudibanisa inokulungelelaniswa ngokufanelekileyo njengoko utshintsho lwamaxesha amaninzi, i-bandwidth ye-antenna encinci inokunyuswa. Ngelixa lo ingengomsebenzi ulula ngokubanzi, kukho izicelo apho unokufezekiswa khona. Owona mzekelo uxhaphakileyo yi-eriyali yerediyo kwirediyo yemoto, edla ngokuba nobude obuhlengahlengiswayo obunokusetyenziselwa ukushunisa i-eriyali ukuze yamkelwe ngcono.
Ukuze ufunde ngakumbi ngee-eriyali, nceda undwendwele:
Ixesha lokuposa: Jul-12-2024
