I-Directivity yiparamitha ye-eriyali esisiseko. Lo ngumlinganiselo wendlela ipateni yemitha ye-eriyali eyalathiswayo. I-eriyali ephuma ngokulinganayo kuwo onke amacala iya kuba ne-directivity elingana no-1. (Oku kufana ne-zero decibels -0 dB).
Umsebenzi wolungelelwaniso lwe-spherical ungabhalwa njengepateni eqhelekileyo yemitha:
[Equation 1]
Ipateni eqhelekileyo yokusasazeka inemilo efanayo neyepateni yokuqala yokusasazeka kwemitha. Ipateni yemitha yesiqhelo icuthwe ngokobukhulu kangangokuba ixabiso eliphezulu lepateni yokusasazeka kwemitha lilingana no-1. (Eyona inkulu yi-equation [1] ka "F"). Ngokwezibalo, indlela yokwalatha (uhlobo "D") ibhalwe ngolu hlobo:
Oku kunokubonakala ngathi yinxaki yendlela enzima. Nangona kunjalo, iipateni zemitha yeemolekyuli zibaluleke kakhulu. Idinomineyitha imele umndilili wamandla asasazwa macala onke. Inxaki ke ngumlinganiselo wencopho yamandla asasazwayo ahlulwe ngomndilili. Oku kunika ulwalathiso lwe-eriyali.
Iparadigm yolwalathiso
Njengomzekelo, qwalasela iiequation ezimbini ezilandelayo zepateni yemitha yee-eriyali ezimbini.
I-antenna 1
I-antenna 2
Ezi patheni zemitha zicwangciswe kuMfanekiso 1. Nceda uqaphele ukuba imowudi yokusasazeka ngumsebenzi wepolar angle theta (θ)Ipateni yemitha ayingomsebenzi we-azimuth. (Ipateni ye-azimuthal radiation ihlala ingatshintshi). Ipateni yemitha ye-eriyali yokuqala ayiqondi kakuhle, emva koko ipateni yemitha ye-eriyali yesibini. Ke ngoko, silindele ukuba ulwalathiso lube sezantsi kwi-eriyali yokuqala.
umfanekiso 1. Umzobo wepateni yemitha ye-eriyali. Inomkhombandlela ophezulu?
Ukusebenzisa ifomula [1], sinokubala ukuba i-eriyali ine-directivity ephezulu. Ukujonga ukuqonda kwakho, cinga ngoMfanekiso 1 kunye nokuba yintoni na indlela. Emva koko misela ukuba yeyiphi i-eriyali enolwalathiso oluphezulu ngaphandle kokusebenzisa naziphi na izibalo.
Iziphumo zokubala ezithe gqolo, sebenzisa ifomula [1]:
I-eriyali yolwalathiso 1 ukubala, 1.273 (1.05 dB).
I-eriyali ye-antenna 2 ukubala, 2.707 (4.32 dB).
Ukwandiswa kwe-directivity kuthetha i-eriyali egxile ngakumbi okanye eyalathiso. Oku kuthetha ukuba i-eriyali yokufumana i-2 inamaxesha angama-2.707 amandla olwalathiso lwencopho yayo kune-antenna ye-omnidirectional. I-antenna 1 iya kufumana amaxesha angama-1.273 amandla e-antenna ye-omnidirectional. Ii-eriyali ze-Omnidirectional zisetyenziswa njengereferensi eqhelekileyo nangona kungekho zi-eriyali ze-isotropic ezikhoyo.
Ii-eriyali zeselfowuni kufuneka zibe ne-directivity ephantsi kuba iimpawu zinokuvela kulo naliphi na icala. Ngokwahlukileyo, izitya zesathelayithi zinokuqondisa okuphezulu. Isitya sesathelayithi sifumana imiqondiso evela kwicala elimiselweyo. Ngokomzekelo, ukuba ufumana isitya seTV se-satellite, inkampani iya kukuxelela apho ungayikhomba khona kwaye isitya siya kufumana isignali oyifunayo.
Siza kugqiba ngoluhlu lweentlobo ze-eriyali kunye nokuqondisa kwazo. Oku kuya kukunika ingcamango yokuba yeyiphi indlela eqhelekileyo.
Uhlobo lwe-eriyali Indlela yokwalatha eqhelekileyo [decibel] (dB)
I-eriyali ye-dipole emfutshane 1.5 1.76
Isiqingatha-amaza dipole eriyali 1.64 2.15
Isiqwenga (i-antenna ye-microstrip) 3.2-6.3 5-8
I-eriyali yophondo 10-100 10-20
Dish eriyali 10-10,000 10-40
Njengoko idatha engentla ibonisa ulwalathiso lwe-eriyali luyahluka kakhulu. Ke ngoko, kubalulekile ukuqonda ukuthe ngqo xa ukhetha eyona eriyali ilungileyo kwisicelo sakho esithile. Ukuba ufuna ukuthumela okanye ukufumana amandla ukusuka kwiindlela ezininzi kwicala elinye kuya kufuneka uyile i-eriyali enokuqondisa okuphantsi. Imizekelo yezicelo zee-eriyali ezisezantsi zibandakanya oonomathotholo bemoto, iiselfowuni, kunye nokufikelela kwi-Intanethi ngaphandle kwamacingo ekhompyuter. Ngakolunye uhlangothi, ukuba wenza i-remote sensing okanye ugqithiso lwamandla ekujoliswe kulo, kuya kufuneka i-eriyali eyalatha kakhulu. Ii-eriyali eziya ngasentla ziya kwandisa ukuhanjiswa kwamandla ukusuka kwicala elifunwayo kunye nokunciphisa imiqondiso evela kwiindlela ezingafunekiyo.
Masithi sifuna i-eriyali ephantsi yokuqondisa. Sikwenza njani oku?
Umgaqo jikelele wethiyori ye-eriyali kukuba udinga i-eriyali encinci yombane ukuvelisa ulwalathiso oluphantsi. Oko kukuthi, ukuba usebenzisa i-eriyali kunye nobukhulu obupheleleyo be-0.25 - 0.5 wavelength, ngoko uya kunciphisa ukuqondisa. Ii-eriyali ze-dipole ezinesiqingatha zamaza okanye ii-eriyali zesiqingatha sobude bobude buhlala bungaphantsi kwe-3 dB ngqo. Oku kuphantsi njengokwalathiso onokulufumana xa usebenza.
Ekugqibeleni, asikwazi ukwenza ii-eriyali zibe zincinci kunekota ye-wavelength ngaphandle kokunciphisa ukusebenza kakuhle kwe-eriyali kunye ne-bandwidth ye-eriyali. Ukusebenza kakuhle kwe-antenna kunye ne-antenna bandwidth iya kuxoxwa kwizahluko ezizayo.
Kwi-eriyali enokwalatha okuphezulu, siya kufuna ii-eriyali ezinobungakanani obuninzi be-wavelength. Njengee-eriyali zesathelayithi zesitya kunye neempondo zeempondo zinokuqondisa okuphezulu. Oku kungenxa yokuba zininzi ubude bamaza.
kutheni kunjalo? Ekugqibeleni, isizathu sinento yokwenza neempawu zenguqu yeFourier. Xa uthatha iFourier transform of short pulse, ufumana i-spectrum ebanzi. Lo mzekeliso awukho ekumiseleni ipateni yemitha ye-eriyali. Ipateni yokusasazeka kwemitha kunokucingelwa njengenguqu yeFourier yosasazo lwangoku okanye amandla ombane ecaleni kwe-eriyali. Ke ngoko, ii-eriyali ezincinci zineepateni ezibanzi zemitha (kunye nolwalathiso oluphantsi). Ii-eriyali ezinevoltheji enkulu efanayo okanye ukuhanjiswa kwangoku Iipateni zalathiso kakhulu (kunye nolwalathiso oluphezulu).
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Ixesha lokuposa: Nov-07-2023
