Lesi sigaba sichaza inqubo yokuhlola ye-TDR

I-TDR isifinyezo se-time-domain Reflectometry.Ubuchwepheshe bokulinganisa berimothi obuhlaziya amagagasi abonisiwe futhi bufunde isimo sento elinganisiwe endaweni yesilawuli kude.Ngaphezu kwalokho, kune-reflectometry yesizinda sesikhathi;Ukudluliselwa kokulibaziseka kwesikhathi;Irejista ye-Transmit Data isetshenziswa kakhulu embonini yezokuxhumana ekuqaleni kwesigaba ukuze kutholwe indawo lapho ikhebula lokuxhumana likuphi, ngakho libuye libizwe ngokuthi “umtshina wekhebula”.I-refleometer yesizinda sesikhathi iyithuluzi le-elekthronikhi elisebenzisa i-refleometer yesizinda sesikhathi ukuze ibonise futhi ithole amaphutha ezintanjeni zensimbi (isibonelo, amakhebuli asontekile noma amakhebuli angama-coaxial).Ingasetshenziswa futhi ukuthola ama-discontinuities kuzixhumi, amabhodi esekethe aphrintiwe, nanoma iyiphi enye indlela kagesi.

I-E5071c-tdr interface yomsebenzisi ingakhiqiza imephu yeso elingisiwe ngaphandle kokusebenzisa ijeneretha yekhodi eyengeziwe;Uma udinga imephu yeso lesikhathi sangempela, engeza ijeneretha yesiginali ukuze uqedele ukulinganisa!I-E5071C inalo msebenzi

Uhlolojikelele lwethiyori yokudlulisa isignali

Eminyakeni yamuva, ngokuthuthukiswa okusheshayo kwesilinganiso esincane sezindinganiso zokuxhumana zedijithali, isibonelo, umthengi olula we-USB 3.1 bit rate waze wafinyelela ku-10Gbps;I-USB4 ithola i-40Gbps;Ukuthuthukiswa kwe-bit rate kwenza izinkinga ezingakaze zibonwe ohlelweni lwedijithali lwendabuko ziqale ukuvela.Izinkinga ezifana nokucabanga nokulahlekelwa zingabangela ukuhlanekezela kwesignali yedijithali, okuholela kumaphutha amancane;Ngaphezu kwalokho, ngenxa yokuncipha kwemajini yesikhathi eyamukelekayo ukuze kuqinisekiswe ukusebenza kahle kwedivayisi, ukuchezuka kwesikhathi kumzila wesiginali kuba kubaluleke kakhulu.I-radiation electromagnetic wave kanye nokuhlangana okukhiqizwe amandla alahlekile kuzoholela ku-crosstalk futhi kwenze idivayisi isebenze kabi.Njengoba izifunda ziba zincane futhi ziqina, lokhu kuba yinkinga kakhulu;Ukwenza izinto zibe zimbi nakakhulu, ukuncishiswa kwe-voltage yokuhlinzeka kuzoholela esilinganisweni esiphansi sesignali-kuya-nomsindo, okwenza idivayisi ibe lula kakhulu umsindo;

Ukuxhumanisa okuqondile kwe-TDR ukuvimbela

I-TDR iphakela igagasi lesinyathelo ukusuka ethekwini ukuya kuyisekethe, kodwa kungani iyunithi emile ye-TDR ingeyona i-voltage kodwa i-impedance?Uma kuyi-impedance, kungani ubona umphetho okhuphukayo?Yiziphi izilinganiso ezenziwa yi-TDR ngokusekelwe ku-Vector Network Analyzer (VNA)?

I-VNA iyithuluzi lokulinganisa impendulo yemvamisa yengxenye elinganisiwe (DUT).Lapho kukala, isignali ye-sinusoidal excitation ifakwa kudivayisi elinganisiwe, bese imiphumela yokulinganisa itholwa ngokubala isilinganiso se-vector amplitude phakathi kwesiginali yokufaka nesignali yokudlulisela (S21) noma isignali ebonisiwe (S11).Izici zokuphendula imvamisa zocingo zingatholwa ngokuskena isignali yokufaka ebangeni lefrikhwensi elinganisiwe.Ukusebenzisa isihlungi se-band pass ekusamukelini sokulinganisa kungasusa umsindo nesiginali engafuneki kumphumela wokulinganisa futhi kuthuthukise ukunemba kokulinganisa.

Umdwebo wohlelo lwesignali yokufaka, isignali ebonisiwe nesignali yokudlulisela

Ngemva kokuhlola idatha, i-IT yatholwa ukuthi ithuluzi le-TDR lenza i-voltage amplitude yegagasi elibonisiwe ijwayelekile, bese ilingana nayo ne-impedance.I-reflection coefficient ρ ilingana ne-voltage ebonisiwe ehlukaniswe i-voltage yokufaka;Ukubonakaliswa kwenzeka lapho i-impedance ingaqhubeki, futhi i-voltage eboniswa emuva ilingana nomehluko phakathi kwama-impedances, futhi i-voltage yokufaka ilingana nesamba se-impedances.Ngakho sinefomula elandelayo.Njengoba imbobo yokukhipha yensimbi ye-TDR ingu-50 ohms, Z0=50 ohms, ngakho-ke u-Z angabalwa, okungukuthi, ijika le-impedance le-TDR elitholwe ngesakhiwo.

Ngakho-ke, emfanekisweni ongenhla, i-impedance ebonwe esigabeni sokuqala sesignali incane kakhulu kune-50 ohms, futhi umthambeko uzinzile onqenqemeni olukhuphukayo, okubonisa ukuthi ukuvimbela okubonwayo kuhambisana nebanga elihanjiwe ngesikhathi sokusakazwa phambili. yesiginali.Ngalesi sikhathi, impedance ayishintshi.Ngicabanga ukuthi kuwukuzungeza ukusho ukuthi kuthathwa njengokungathi unqenqema olukhuphukayo lwamuncwa ngemuva kokwehliswa kwe-impedance, futhi ekugcineni lwehliswa.Endleleni elandelayo ye-impedance ephansi, yaqala ukukhombisa izici zomphetho okhuphukayo futhi yaqhubeka nokukhuphuka.Bese i-impedance idlula ama-ohms angu-50, ngakho-ke isignali idlula kancane, bese ibuya kancane kancane, futhi ekugcineni izinzile kuma-ohms angu-50, futhi isignali isifinyelele kwelinye ichweba.Ngokuvamile, isifunda lapho i-impedance yehla khona ingacatshangwa ukuthi inomthwalo we-capacitive emhlabathini.Isifunda lapho i-impedance inyuka ngokuzumayo ingacatshangwa njengene-inductor ochungechungeni.