I-TDR isifinyezo se-time-domain Reflectometry. Iwubuchwepheshe bokulinganisa obukude obuhlaziya amaza abonakalayo futhi bufunde isimo sento elinganisiwe endaweni yokulawula kude. Ngaphezu kwalokho, kukhona i-time domain reflectometry; i-Time-delay relay; i-Transmit Data Register isetshenziswa kakhulu embonini yezokuxhumana esigabeni sokuqala ukuthola indawo yokuphuka kwekhebula lokuxhumana, ngakho-ke ibizwa nangokuthi "i-cable detector". I-time domain reflectometer iyithuluzi le-elekthronikhi elisebenzisa i-time domain reflectometer ukuchaza nokuthola amaphutha ezintanjeni zensimbi (isibonelo, izintambo ezisontekile noma izintambo ze-coaxial). Ingasetshenziswa futhi ukuthola ama-discontinuities ezixhumini, amabhodi wesekethe aphrintiwe, noma kunoma iyiphi enye indlela kagesi.
Isixhumi esibonakalayo somsebenzisi se-E5071c-tdr singakha imephu yamehlo elingisiwe ngaphandle kokusebenzisa i-generator yekhodi eyengeziwe; Uma udinga imephu yamehlo yesikhathi sangempela, engeza i-generator yesignali ukuze uqedele ukulinganisa! I-E5071C inalo msebenzi
Ukubuka konke kwethiyori yokudlulisa isignali
Eminyakeni yamuva nje, ngokuthuthuka okusheshayo kwesilinganiso se-bit sezindinganiso zokuxhumana zedijithali, isibonelo, izinga le-USB 3.1 bit elilula kakhulu labathengi lifinyelele ngisho ku-10Gbps; i-USB4 ithola i-40Gbps; Ukuthuthukiswa kwesilinganiso se-bit kwenza izinkinga ezingakaze zibonwe ohlelweni lwedijithali lwendabuko ziqale ukuvela. Izinkinga ezifana nokuzindla nokulahlekelwa zingabangela ukuphambuka kwesignali yedijithali, okuholela emaphutheni e-bit; Ngaphezu kwalokho, ngenxa yokwehla kwesilinganiso sesikhathi esamukelekayo ukuqinisekisa ukusebenza kahle kwedivayisi, ukuphambuka kwesikhathi endleleni yesignali kuba kubaluleke kakhulu. Igagasi le-electromagnetic elikhipha imisebe kanye nokuxhuma okukhiqizwa yi-capacitance elahlekile kuzoholela ekukhulumeni okuphambene futhi kwenze idivayisi isebenze kabi. Njengoba amasekethe eba mancane futhi eqina, lokhu kuba yinkinga enkulu; Okwenza izinto zibe zimbi kakhulu, ukwehla kwe-voltage yokuphakelwa kuzoholela esilinganisweni esiphansi sesignali kuya kumsindo, okwenza idivayisi ibe sengozini enkulu yomsindo;
I-coordinate eqondile ye-TDR yi-impedance
I-TDR yondla igagasi lesinyathelo kusukela echwebeni kuya kusekethe, kodwa kungani iyunithi eqondile ye-TDR ingeyona i-voltage kodwa i-impedance? Uma kuyi-impedance, kungani ungabona umkhawulo okhuphukayo? Yiziphi izilinganiso ezenziwa yi-TDR ngokusekelwe ku-Vector Network Analyzer (VNA)?
I-VNA iyithuluzi lokulinganisa impendulo yemvamisa yengxenye elinganisiwe (i-DUT). Uma kulinganiswa, isignali yokuvuselela i-sinusoidal ifakwa kudivayisi elinganisiwe, bese imiphumela yokulinganisa itholakala ngokubala isilinganiso se-vector amplitude phakathi kwesignali yokufaka kanye nesignali yokudlulisa (i-S21) noma isignali ebonisiwe (i-S11). Izici zokuphendula kwemvamisa zedivayisi zingatholakala ngokuskena isignali yokufaka ebangeni lemvamisa elinganisiwe. Ukusebenzisa isihlungi se-band pass kumukeli wokulinganisa kungasusa umsindo kanye nesignali engafuneki emiphumeleni yokulinganisa futhi kuthuthukise ukunemba kokulinganisa.
Umdwebo weskimu wesiginali yokufaka, isiginali ebonisiwe kanye nesiginali yokudlulisa
Ngemva kokuhlola idatha, kwatholakala ukuthi ithuluzi le-TDR lenze i-voltage amplitude yegagasi elibonakalayo yajwayelekile, bese lilingana ne-impedance. I-coefficient yokubonakalisa i-ρ ilingana ne-voltage eboniswayo ehlukaniswe yi-voltage yokufaka; Ukuzindla kwenzeka lapho i-impedance ingaqhubeki khona, futhi i-voltage eboniswa emuva ilingana nomehluko phakathi kwe-impedances, kanti i-voltage yokufaka ilingana nesamba se-impedances. Ngakho-ke sinefomula elandelayo. Njengoba i-port yokukhipha yethuluzi le-TDR ingu-50 ohms, i-Z0=50 ohms, ngakho-ke i-Z ingabalwa, okungukuthi, i-impedance curve ye-TDR etholwe ngesakhiwo.
Ngakho-ke, esithombeni esingenhla, i-impedance ebonwe esigabeni sokuqala sesigameko sesignali incane kakhulu kune-50 ohms, futhi umthambeka uzinzile eceleni komphetho okhuphukayo, okubonisa ukuthi i-impedance ebonwayo ilingana nebanga elihanjiwe ngesikhathi sokusabalala kwesignali phambili. Phakathi nalesi sikhathi, i-impedance ayishintshi. Ngicabanga ukuthi kuyinto ejikelezayo ukusho ukuthi kubhekwa njengokungathi umphetho okhuphukayo wadonswa ngemuva kokunciphisa i-impedance, futhi ekugcineni wehliswa ijubane. Endleleni elandelayo ye-impedance ephansi, yaqala ukukhombisa izici zomphetho okhuphukayo yaqhubeka nokukhuphuka. Bese i-impedance idlula ama-ohms angu-50, ngakho-ke isignali idlula kancane, bese ibuya kancane, futhi ekugcineni izinze kuma-ohms angu-50, futhi isignali ifinyelele echwebeni eliphambene. Ngokuvamile, isifunda lapho i-impedance yehla khona ingacatshangwa njengesinomthwalo we-capacitive phansi. Isifunda lapho i-impedance ikhula khona ngokuzumayo singacatshangwa njengesine-inductor ochungechungeni.
Isikhathi sokuthunyelwe: Agasti-16-2022
