20.500.12556/RUL-173649 Detekcija jedrske magnetne resonance Nuclear magnetic resonance detection V nalogi je predstavljen prototipni sistem za zaznavanje jedrske magnetne resonance (NMR) v homogeni reži permanentnega magneta z gostoto magnetnega pretoka 0,3 T. Sistem združuje strojni in programski del: vir nosilne frekvence na osnovi Si5351A z 26 MHz TCXO v celoštevilskem-PLL načinu in z dvema fazno zamaknjenima izhodoma, merilno sondo z uglašenim LC krogom, pasivni diodni mešalnik za I/Q pretvorbo, nizkošumno ojačevalno-filtrirno verigo. Statično magnetno polje se modulira z 70 Hz, sinusni signal pa generira 12-bitni DAC iz vpogledne tabele. Programska oprema krmili frekvenco in izračuna magnetno polje. Radiofrekvenčni del vezja je montiran v aluminjastem ohišju. Predlagana je nadgradnja za samostojno zaznavanje in sledenjem resonance na osnovi signala napake iz sinhrone detekcije, kar bi zmanjšalo vpliv lezenja magneta. This work presents a prototype system for detecting nuclear magnetic resonance (NMR) in the homogeneous air gap of a permanent magnet with a magnetic flux density of 0.3 T. The system integrates hardware and firmware: a Si5351A-based carrier source with a 26 MHz TCXO operated in integer-PLL mode and providing two quadrature outputs; a measurement probe with a tuned LC resonator; a passive diode mixer for I/Q conversion; a low-noise amplification and filtering chain. The static field is modulated at 70 Hz, with the sinusoid synthesized by a 12-bit DAC using a lookup table. The firmware controls the frequency, and computes the magnetic field. The RF section is mounted in an aluminium enclosure. An upgrade is proposed toward autonomous detection, and tracking of the resonance based on the error signal from synchronous detection, which would reduce the influence of magnet drift. jedrska magnetna resonanca merjenje gostote magnetnega pretoka Si5351A I/Q mešalnik TCXO STM32 nuclear magnetic resonance magnetic flux density measurement Si5351A I/Q mixer TCXO STM32 true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2025-09-19 11:15:27 2025-09-19 11:15:33 2025-11-11 03:57:10 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 62874 252121859 Cehovin_Jakob_-_Detekcija_jedrske_magnetne_resonance.pdf Cehovin_Jakob_-_Detekcija_jedrske_magnetne_resonance.pdf 1 B81C6F2206155BB142E6FA4A4DBAF83A 935d06e827af12d9cfa165c46be932ec1c42383260fdb9cd00833af5de168292 069f63a9-9539-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=218268 Fakulteta za elektrotehniko 0 0 0