TDR ndi chidule cha nthawi-domain Reflectometry. Ndi ukadaulo woyezera kutali womwe umasanthula mafunde owonetsedwa ndikuphunzira momwe chinthu choyezedwa chilili pamalo owongolera kutali. Kuphatikiza apo, pali nthawi yowunikira nthawi; nthawi yowunikira nthawi; Kutumiza Deta Register imagwiritsidwa ntchito makamaka mumakampani olumikizirana poyambirira kuti azindikire malo osweka a chingwe cholumikizirana, kotero chimatchedwanso "chowunikira chingwe". Chiwonetsero cha nthawi ndi chida chamagetsi chomwe chimagwiritsa ntchito chowunikira nthawi kuti chizindikire ndikupeza zolakwika mu zingwe zachitsulo (monga, zingwe zopotoka kapena zingwe za coaxial). Chingagwiritsidwenso ntchito kupeza ma discontinuities mu zolumikizira, ma circuit board osindikizidwa, kapena njira ina iliyonse yamagetsi.
Chida chogwiritsira ntchito cha E5071c-tdr chingathe kupanga mapu oyeserera maso popanda kugwiritsa ntchito makina ena opangira ma code; Ngati mukufuna mapu enieni a maso, onjezani makina opangira ma signal kuti muyeze bwino! E5071C ili ndi ntchito iyi
Chidule cha chiphunzitso chotumizira zizindikiro
M'zaka zaposachedwapa, chifukwa cha kusintha kwachangu kwa bit rate ya miyezo yolumikizirana ya digito, mwachitsanzo, USB 3.1 bit rate yosavuta kwambiri ya ogwiritsa ntchito yafika pa 10Gbps; USB4 imapeza 40Gbps; Kukwera kwa bit rate kumapangitsa kuti mavuto omwe sanawonekepo mu dongosolo la digito lachikhalidwe ayambe kuwonekera. Mavuto monga kuwunikira ndi kutayika angayambitse kusokonekera kwa chizindikiro cha digito, zomwe zimapangitsa kuti zikhale zolakwika; Kuphatikiza apo, chifukwa cha kuchepa kwa nthawi yovomerezeka kuti zitsimikizire kuti chipangizocho chikugwira ntchito moyenera, kupotoka kwa nthawi munjira ya chizindikiro kumakhala kofunikira kwambiri. Mafunde amagetsi a radiation ndi coupling omwe amapangidwa ndi capacitance yosochera zimabweretsa kufalikira kwa mawu ndikupangitsa chipangizocho kugwira ntchito molakwika. Pamene ma circuits akuyamba kuchepa, izi zimakhala vuto lalikulu; Kuti zinthu ziipireipire, kuchepa kwa magetsi operekera kudzapangitsa kuti chiŵerengero cha chizindikiro ndi phokoso chikhale chochepa, zomwe zimapangitsa chipangizocho kukhala chosavuta kukhudzidwa ndi phokoso;
Chogwirizanitsa choyimirira cha TDR ndi impedance
TDR imapatsa mafunde oyenda kuchokera ku doko kupita ku dera, koma nchifukwa chiyani gawo loyima la TDR si voltage koma impedance? Ngati ndi impedance, nchifukwa chiyani mungathe kuwona m'mphepete wokwera? Ndi miyeso iti yomwe TDR imapangidwa kutengera Vector Network Analyzer (VNA)?
VNA ndi chida choyezera kuyankha kwafupipafupi kwa gawo loyesedwa (DUT). Poyezera, chizindikiro choyambitsa sinusoidal chimalowetsedwa ku chipangizo choyezedwa, kenako zotsatira za muyeso zimapezeka powerengera chiŵerengero cha ma amplitude a vector pakati pa chizindikiro cholowetsedwa ndi chizindikiro chotumizira (S21) kapena chizindikiro chowonetsedwa (S11). Makhalidwe a kuyankha kwafupipafupi kwa chipangizocho angapezeke posanthula chizindikiro cholowetsedwa mu range yoyesedwa yafupipafupi. Kugwiritsa ntchito fyuluta ya band pass mu cholandirira choyezera kungachotse phokoso ndi chizindikiro chosafunikira kuchokera ku zotsatira zoyezera ndikuwongolera kulondola kwa kuyeza.
Chithunzi chojambula cha chizindikiro cholowera, chizindikiro chowonetsedwa ndi chizindikiro chotumizira
Pambuyo pofufuza deta, IT idapezeka kuti chida cha TDR chidasintha mphamvu ya ma voltage ya mafunde owonetsedwa, kenako nkuchifananiza ndi impedance. Coefficient yowunikira ρ ndi yofanana ndi mphamvu ya ma voltage yowonetsedwa yogawidwa ndi mphamvu ya input; Kuwunikira kumachitika pomwe impedance siikupitirira, ndipo mphamvu ya ma voltage yowunikira kumbuyo ikugwirizana ndi kusiyana pakati pa ma impedance, ndipo mphamvu ya ma voltage yowunikira ikugwirizana ndi kuchuluka kwa ma impedance. Chifukwa chake tili ndi njira yotsatirayi. Popeza doko lotulutsa la chida cha TDR ndi 50 ohms, Z0=50 ohms, kotero Z ikhoza kuwerengedwa, ndiko kuti, curve ya impedance ya TDR yopezedwa ndi plot.
Chifukwa chake, pachithunzi pamwambapa, impedance yomwe imawoneka pagawo loyamba la chizindikiro ndi yaying'ono kwambiri kuposa 50 ohms, ndipo malo otsetsereka ndi okhazikika m'mphepete mokwera, zomwe zikusonyeza kuti impedance yomwe ikuwoneka ikugwirizana ndi mtunda womwe wayenda panthawi yofalitsa chizindikiro. Panthawiyi, impedance sikusintha. Ndikuganiza kuti ndi roundabout kunena kuti imawonedwa ngati kuti m'mphepete mokwera idakokedwa pambuyo pa kuchepetsa impedance, ndipo pamapeto pake idachedwa. Panjira yotsatira ya impedance yotsika, idayamba kuwonetsa mawonekedwe a m'mphepete mokwera ndipo idapitilira kukwera. Kenako impedance imapitirira 50 ohms, kotero chizindikirocho chimapitilira pang'ono, kenako chimabwerera pang'onopang'ono, ndipo pamapeto pake chimakhazikika pa 50 ohms, ndipo chizindikirocho chafika pa doko lina. Kawirikawiri, dera lomwe impedance imatsika lingaganizidwe kuti lili ndi katundu wonyamula pansi. Dera lomwe impedance imawonjezeka mwadzidzidzi lingaganizidwe kuti lili ndi inductor motsatizana.
Nthawi yotumizira: Ogasiti-16-2022
