I-antennaukulinganisa yinkqubo yokuvavanya nokuhlaziya ukusebenza kwe-antenna ngobuninzi kunye neempawu zayo. Ngokusebenzisa izixhobo zovavanyo ezikhethekileyo kunye neendlela zokulinganisa, silinganisa i-gain, ipatheni yemitha, umlinganiselo wamaza okuma, impendulo yefrikhwensi kunye nezinye iiparameter ze-antenna ukuqinisekisa ukuba iinkcukacha zoyilo lwe-antenna ziyahlangabezana neemfuno, sijonge ukusebenza kwe-antenna, kwaye sinike iingcebiso zokuphucula. Iziphumo kunye nedatha evela kumlinganiselo we-antenna ingasetyenziselwa ukuvavanya ukusebenza kwe-antenna, ukuphucula uyilo, ukuphucula ukusebenza kwenkqubo, kunye nokubonelela ngesikhokelo kunye nempendulo kubavelisi be-antenna kunye neenjineli zesicelo.
Izixhobo ezifunekayo kwimilinganiselo ye-Antenna
Uvavanyo lwe-antenna, isixhobo esisisiseko yi-VNA. Uhlobo olulula lwe-VNA yi-VNA ene-port enye, ekwaziyo ukulinganisa i-impedance ye-antenna.
Ukulinganisa ipateni yemitha ye-antenna, inzuzo kunye nokusebenza kakuhle kunzima ngakumbi kwaye kufuna izixhobo ezininzi. Siza kubiza i-antenna ukuba ilinganiswe yi-AUT, emele i-Antenna Under Test. Izixhobo ezifunekayo zokulinganisa i-antenna ziquka:
I-antenna yokubhekisa - I-antenna eneempawu ezaziwayo (ukwanda, ipateni, njl.njl.)
I-RF Power Transmitter - Indlela yokufaka amandla kwi-AUT [I-Antenna Iphantsi kovavanyo]
Inkqubo yokwamkela - Oku kumisela ukuba ingakanani amandla afunyanwa yi-antenna yesalathiso
Inkqubo yokubeka indawo - Le nkqubo isetyenziselwa ukujikeleza i-antenna yovavanyo xa ithelekiswa ne-antenna yomthombo, ukulinganisa ipateni yemitha njengomsebenzi we-engile.
Umzobo webhloko wezixhobo ezingentla uboniswe kuMfanekiso 1.
Umfanekiso 1. Umzobo wezixhobo zokulinganisa i-antenna ezifunekayo.
Ezi zinto ziza kuxutyushwa ngokufutshane. I-Antenna yeReference kufuneka ikhanye kakuhle kwi-frequency yovavanyo olufunekayo. Ii-antenna zeReference zihlala zii-antenna ze-horn ezine-polarized ezimbini, ukuze i-polarization ethe tye nethe nkqo ilinganiswe ngaxeshanye.
Inkqubo yokudlulisa kufuneka ikwazi ukukhupha inqanaba lamandla elizinzileyo nelaziwayo. I-frequency yokukhupha kufuneka ikwazi ukuhlengahlengiswa (ikhetheke), kwaye izinzile ngokufanelekileyo (izinzile kuthetha ukuba i-frequency oyifumana kwi-transmitter ikufutshane ne-frequency oyifunayo, ayifani kakhulu nobushushu). I-transmitter kufuneka ibe namandla amancinci kakhulu kuzo zonke ezinye ii-frequency (kuya kuhlala kukho amandla angaphandle kwe-frequency oyifunayo, kodwa akufuneki kubekho amandla amaninzi kwi-harmonics, umzekelo).
Inkqubo Yokwamkela ifuna nje ukumisela ukuba ingakanani amandla afunyanwa kwi-antenna yovavanyo. Oku kungenziwa ngemitha yamandla elula, esisixhobo sokulinganisa amandla e-RF (i-radio frequency) kwaye inokuqhagamshelwa ngqo kwii-terminals ze-antenna ngomgca wokudlulisela (njengentambo ye-coaxial enezihlanganisi ze-N-type okanye ze-SMA). Ngokwesiqhelo i-receiver yinkqubo ye-50 Ohm, kodwa ingaba yi-impedance eyahlukileyo ukuba ichaziwe.
Qaphela ukuba inkqubo yokudlulisa/yokwamkela idla ngokuthathelwa indawo yi-VNA. Umlinganiselo we-S21 udlulisa i-frequency ngaphandle kwe-port 1 kwaye urekhoda amandla afunyenweyo kwi-port 2. Ngenxa yoko, i-VNA ifanelekile kulo msebenzi; nangona kunjalo, ayisiyo kuphela indlela yokwenza lo msebenzi.
Inkqubo yokuBeka ilawula indlela i-antenna yovavanyo ejikeleziswa ngayo. Ekubeni sifuna ukulinganisa ipateni yemitha ye-antenna yovavanyo njengomsebenzi we-engile (ngesiqhelo kwii-coordinates ezijikelezayo), kufuneka sijikeleze i-antenna yovavanyo ukuze i-antenna yomthombo ikhanyise i-antenna yovavanyo kuzo zonke ii-engile ezinokwenzeka. Inkqubo yokuBeka isetyenziselwa le njongo. KuMfanekiso 1, sibonisa i-AUT ejikeleziswayo. Qaphela ukuba kukho iindlela ezininzi zokwenza olu jikelezo; ngamanye amaxesha i-antenna yokubhekisa iyajikeleziswa, kwaye ngamanye amaxesha zombini i-antenna yokubhekisa kunye ne-AUT ziyajikeleziswa.
Ngoku ekubeni sinazo zonke izixhobo ezifunekayo, singaxoxa ngendawo yokulinganisa.
Iphi indawo elungileyo yokulinganisa i-antenna yethu? Mhlawumbi ungathanda ukwenza oku kwigaraji yakho, kodwa ukubonakalisa okuvela eludongeni, eluphahleni nasezantsi kungenza ukulinganisa kwakho kungachaneki. Indawo efanelekileyo yokwenza ukulinganisa i-antenna yindawo ethile engaphandle, apho kungenzeki ukubonakalisa. Nangona kunjalo, ngenxa yokuba ukuhamba esibhakabhakeni ngoku kubiza kakhulu, siza kugxila kwiindawo zokulinganisa ezikumphezulu woMhlaba. I-Anechoic Chamber ingasetyenziselwa ukwahlukanisa ukuseta uvavanyo lwe-antenna ngelixa ifunxa amandla abonakalisiweyo nge-RF absorbing foam.
IiNdawo zeSithuba eziKhululekileyo (Anechoic Chambers)
Ii-free space ranges ziindawo zokulinganisa i-antenna ezenzelwe ukulinganisa imilinganiselo eza kwenziwa esibhakabhakeni. Oko kukuthi, onke amaza abonakalisiweyo avela kwizinto ezikufutshane nomhlaba (ezingafunekiyo) acinezelwe kangangoko. Ii-free space ranges ezidumileyo zii-anechoic chambers, ii-highed ranges, kunye ne-compact range.
Amagumbi e-Anechoic
Iigumbi ezine-anechoic zii-antenna zangaphakathi. Iindonga, iisilingi kunye nomgangatho zigcwele izinto ezikhethekileyo zokufunxa amaza e-electromagnetic. Iigumbi zangaphakathi ziyathandeka kuba iimeko zovavanyo zinokulawulwa ngokuqinileyo kunezo zangaphandle. Izinto ezisetyenziswayo zihlala zijijekile, nto leyo eyenza la magumbi abe nomtsalane kakhulu ukuwabona. Iimo zenxantathu ezijijekileyo zenzelwe ukuba oko kuboniswayo kuzo kuthambekele ekusasazekeni kwiindlela ezingacwangciswanga, kwaye oko kongezwa kunye kuzo zonke ii-random reflections kudla ngokongeza ngokungangqalanga kwaye ngaloo ndlela kucinezelwe ngakumbi. Umfanekiso wegumbi eline-anechoic uboniswe kumfanekiso olandelayo, kunye nezixhobo zovavanyo:
(Umfanekiso ubonisa uvavanyo lwe-antenna ye-RFMISO)
Ingxaki kwiigumbi ezingenamoya kukuba zihlala zifuna ukuba zikhulu kakhulu. Amaxesha amaninzi ii-antenna kufuneka zibe zii-wavelengths ezininzi kude enye kwenye ubuncinane ukuze zifane neemeko zasentsimini ezikude. Ngenxa yoko, kwiifrequencies eziphantsi ezinee-wavelengths ezinkulu sifuna iigumbi ezinkulu kakhulu, kodwa iindleko kunye nemida yokusebenza zihlala zinciphisa ubukhulu bazo. Ezinye iinkampani eziqesha ukhuselo ezilinganisa iRadar Cross Section yeenqwelo-moya ezinkulu okanye ezinye izinto zaziwa ngokuba neegumbi ezingenamoya ezinobukhulu beenkundla zebhasikithi, nangona oku kungeyonto iqhelekileyo. Iiyunivesithi ezineegumbi ezingenamoya zihlala zinamagumbi anobude obuziimitha ezi-3-5, ububanzi kunye nokuphakama. Ngenxa yobunzima bobukhulu, kwaye ngenxa yokuba izinto ezifunxa i-RF zihlala zisebenza kakuhle kwi-UHF nangaphezulu, iigumbi ezingenamoya zihlala zisetyenziswa kwiifrequencies ezingaphezulu kwe-300 MHz.
IiRanges Eziphakamileyo
Ii-Elevated Ranges zii-outdoor ranges. Kolu lungiselelo, umthombo kunye ne-antenna evavanywayo zixhonywe ngaphezu komhlaba. Ezi antenna zinokuba kwiintaba, iinqaba, izakhiwo, okanye naphi na apho umntu afumana khona ukuba kufanelekile. Oku kudla ngokwenziwa kwii-antenna ezinkulu kakhulu okanye kwii-frequency eziphantsi (VHF nangaphantsi, <100 MHz) apho imilinganiselo yangaphakathi ingenakulungiseka. Umzobo osisiseko woluhlu oluphakanyisiweyo uboniswe kuMfanekiso 2.
Umfanekiso 2. Umfanekiso woluhlu oluphezulu.
I-antenna yomthombo (okanye i-antenna yokubonisa) ayifanele ibe kwindawo ephakamileyo kune-antenna yovavanyo, ndiyibonise ngolo hlobo apha. Umgca wokubona (LOS) phakathi kwee-antenna ezimbini (eziboniswe yi-black ray kuMfanekiso 2) kufuneka ungaphazanyiswa. Zonke ezinye ii-reflections (ezifana ne-red ray eboniswa emhlabeni) azifuneki. Kwii-ranges eziphakamileyo, xa umthombo kunye nendawo ye-antenna yovavanyo zichongiwe, abaqhubi bovavanyo emva koko bamisela apho ii-reflections ezibalulekileyo ziya kwenzeka khona, kwaye bazame ukunciphisa ii-reflections ezivela kwezi ndawo. Rhoqo izinto ezifunxa i-rf zisetyenziselwa le njongo, okanye ezinye izinto ezisusa i-ray kwi-antenna yovavanyo.
Iindidi eziNcinci
I-antenna yomthombo kufuneka ibekwe kwindawo ekude ye-antenna yovavanyo. Isizathu kukuba igagasi elifunyenwe yi-antenna yovavanyo kufuneka libe yi-plane wave ukuze kube nokuchaneka okuphezulu. Ekubeni ii-antenna zikhupha amaza angqukuva, i-antenna kufuneka ibe kude ngokwaneleyo kangangokuba igagasi eliphuma kwi-antenna yomthombo limalunga ne-plane wave - jonga uMfanekiso 3.
Umfanekiso 3. I-antenna yomthombo ikhupha amaza ane-wavefront engqukuva.
Nangona kunjalo, kwiigumbi zangaphakathi kudla ngokungabikho ukwahlukana okwaneleyo ukufezekisa oku. Enye indlela yokulungisa le ngxaki kukusebenzisa uluhlu oluncinci. Kule ndlela, i-antenna yomthombo ijoliswa kwi-reflector, enemilo eyenzelwe ukubonakalisa i-spherical wave ngendlela ephantse icwangciswe. Oku kufana kakhulu nomgaqo osebenza ngawo i-antenna yesitya. Umsebenzi osisiseko uboniswe kuMfanekiso 4.
Umfanekiso 4. Ububanzi Obuncinci - amaza angqukuva avela kwi-antenna yomthombo abonakaliswa njenge-planar (collimated).
Ubude be-parabolic reflector budla ngokufunwa ukuba bube bukhulu ngokuphindwe kaninzi kune-antenna yovavanyo. I-antenna yomthombo kuMfanekiso 4 ithintelwe kwi-reflector ukuze ingaphazamisi imisebe eboniswayo. Kufuneka kuqatshelwe kwakhona ukuze kugcinwe nayiphi na imitha ethe ngqo (i-mutual coupling) ukusuka kwi-antenna yomthombo ukuya kwi-antenna yovavanyo.
Ixesha leposi: Jan-03-2024
