Eli candelo lichaza inkqubo yovavanyo lwe-TDR

I-TDR sisifinyezo se-time-domain Reflectometry. Yiteknoloji yokulinganisa ekude ehlalutya amaza abonakalisiweyo kwaye ifunde imeko yento elinganisiweyo kwindawo yokulawula kude. Ukongeza, kukho i-time domain reflectometry; i-Time-delay relay; i-Transmit Data Register isetyenziswa kakhulu kushishino lonxibelelwano kwisigaba sokuqala ukufumanisa indawo yokuqhekeka kwentambo yonxibelelwano, ngoko ke ikwabizwa ngokuba yi-"cable detector". I-time domain reflectometer sisixhobo se-elektroniki esisebenzisa i-time domain reflectometer ukuchaza nokufumanisa iimpazamo kwiintambo zesinyithi (umzekelo, iintambo ezijijekileyo okanye iintambo ze-coaxial). Ingasetyenziselwa ukufumana ukungaqhubeki kwii-connectors, iibhodi zesekethe eziprintiweyo, okanye nakweyiphi na enye indlela yombane.

I-interface yomsebenzisi ye-E5071c-tdr inokuvelisa imephu yamehlo eqikelelweyo ngaphandle kokusebenzisa i-code generator eyongezelelweyo; Ukuba ufuna imephu yamehlo yexesha langempela, yongeza i-signal generator ukuze ugqibezele ukulinganisa! I-E5071C inalo msebenzi

Isishwankathelo sethiyori yokudluliselwa kwesignali

Kwiminyaka yakutshanje, ngokuphuculwa ngokukhawuleza kwesantya se-bit yemigangatho yonxibelelwano lwedijithali, umzekelo, isantya se-USB 3.1 bit esilula sabathengi safikelela kwi-10Gbps; i-USB4 ifumana i-40Gbps; Ukuphuculwa kwesantya se-bit kwenza iingxaki ezingazange zibonwe kwinkqubo yedijithali yendabuko ziqale ukubonakala. Iingxaki ezinje ngokuqaqambisa kunye nokulahleka zinokubangela ukuphazamiseka kwesignali yedijithali, okubangela iimpazamo ze-bit; Ukongeza, ngenxa yokuncipha komda wexesha owamkelekileyo ukuqinisekisa ukusebenza ngokuchanekileyo kwesixhobo, ukuphambuka kwexesha kwindlela yesignali kubaluleke kakhulu. I-radiation electromagnetic wave kunye ne-coupling eveliswa yi-stray capacitance iya kukhokelela kwi-crosstalk kwaye yenze isixhobo sisebenze gwenxa. Njengoko iisekethe zisiba ncinci kwaye ziqina, oku kuba yingxaki ngakumbi; Ukwenza izinto zibe mbi ngakumbi, ukwehla kwe-supply voltage kuya kubangela umlinganiselo ophantsi wesignali-kwingxolo, okwenza isixhobo sibe sesichengeni ngakumbi kwingxolo;

I-coordinate ethe nkqo ye-TDR yi-impedance

I-TDR yondla i-step wave ukusuka kwi-port ukuya kwi-circuit, kodwa kutheni iyunithi ethe nkqo ye-TDR ingeyona i-voltage kodwa i-impedance? Ukuba yi-impedance, kutheni ubona umda onyukayo? Zeziphi izilinganiso ezenziwa yi-TDR ngokusekelwe kwi-Vector Network Analyzer (VNA)?

I-VNA sisixhobo sokulinganisa impendulo yemvamisa yenxalenye elinganisiweyo (i-DUT). Xa kulinganiswa, isignali yokuvuselela ye-sinusoidal ifakwa kwisixhobo esilinganisiweyo, kwaye emva koko iziphumo zokulinganisa zifunyanwa ngokubala umlinganiselo we-vector amplitude phakathi kwesignali yokufaka kunye nesignali yokudlulisa (i-S21) okanye isignali ebonakalisiweyo (i-S11). Iimpawu zempendulo yemvamisa yesixhobo zinokufunyanwa ngokuskena isignali yokufaka kuluhlu lwemvamisa elinganisiweyo. Ukusebenzisa isihluzo sebhendi kwireceiver yokulinganisa kunokususa ingxolo kunye nesignali engafunekiyo kwisiphumo sokulinganisa kwaye kuphuculwe ukuchaneka kokulinganisa.

Umzobo weskimu wesiginali yokufaka, isiginali ebonakalisiweyo kunye nesiginali yokudlulisela

Emva kokujonga idatha, kwafunyaniswa ukuba isixhobo se-TDR silinganisele ubungakanani be-voltage ye-reflective wave, saza sayilinganisa ne-impedance. I-reflection coefficient ρ ilingana ne-reflective voltage eyahlulwe yi-input voltage; I-Reflection yenzeka apho i-impedance ingaqhubeki, kwaye i-voltage reflective back ilingana nomahluko phakathi kwe-impedances, kwaye i-input voltage ilingana ne-sum ye-impedances. Ngoko ke sinefomyula elandelayo. Ekubeni i-output port ye-TDR instrument yi-50 ohms, i-Z0=50 ohms, ngoko ke i-Z ingabalwa, oko kukuthi, i-impedance curve ye-TDR efunyenwe nge-plot.

Ke ngoko, kumfanekiso ongentla, i-impedance ebonwe kwinqanaba lokuqala lesiganeko sesignali incinci kakhulu kune-50 ohms, kwaye ithambeka lizinzile ecaleni komphetho onyukayo, nto leyo ebonisa ukuba i-impedance ebonwayo ilingana nomgama ohanjiweyo ngexesha lokusasazeka kwesignali phambili. Ngeli xesha, i-impedance ayitshintshi. Ndicinga ukuba kuyinto ejikelezayo ukuthi kuthathwa njengokuba umphetho onyukayo utsalwe emva kokunciphisa i-impedance, kwaye ekugqibeleni wehliswa isantya. Kwindlela elandelayo ye-impedance ephantsi, yaqala ukubonisa iimpawu zomphetho onyukayo yaza yaqhubeka nokunyuka. Emva koko i-impedance idlula i-50 ohms, ngoko ke isignali idlula kancinci, emva koko ibuye kancinci, kwaye ekugqibeleni izinze kwi-50 ohms, kwaye isignali ifikelele kwizibuko elichaseneyo. Ngokubanzi, ummandla apho i-impedance iwela khona unokucingwa njengonomthwalo we-capacitive emhlabeni. Ummandla apho i-impedance inyuka ngequbuliso unokucingwa njengone-inductor kuthotho.