In this paper, we present a CMOS-based miniaturized magnetic resonance (MR) system for magnetic field and trajectory mapping incorporating an electromagnetic interference (EMI) robust optical link. The system consists of a custom-designed, CMOS-based active NMR field probe, a custom-designed, single-bit ΣΔ modulator and a commercial optical link. The low-IF architecture of the transceiver ASIC, reduces the required bandwidth in the digitizer to a few hundred kilohertz, enabling the use of a single-bit ΣΔ modulator, whose high frequency, one bit data stream is ideally suited for feeding the following optical link. The custom ΣΔ modulator uses a third order loop filter and employs a 12-tap FIR DAC to increase its robustness against clock jitter. It is manufactured in a 0.18 μm CMOS technology and achieves an SNDR of 72.19 dB over a Nyquist bandwidth of 800 kHz. In the proposed setup, the 1-bit output stream of the ΣΔ modulator directly feeds the driver of a commercial optical fiber link to transmit the NMR data from inside the NMR magnet to the remotely located digital signal processing unit with a very high robustness against EMI. In-situ NMR experiments with a 1.45 T benchtop magnet using a silicone sample demonstrate the very good performance of the overall system, achieving a frequency resolution of 12.6 Hz or 200 ppb in the estimation of the sample's NMR resonance frequency. This corresponds to an effective magnetic field resolution of 290 nT.
%0 Conference Paper
%1 9181026
%A Zhao, J.
%A Mohamed, A.
%A Anders, J.
%B 2020 IEEE International Symposium on Circuits and Systems (ISCAS)
%D 2020
%K myown iis from:aymanmohamed
%P 1-5
%R 10.1109/ISCAS45731.2020.9181026
%T An Active CMOS NMR Field Probe with Custom Transceiver and ΣΔ Modulator ASICs and an Optical Link
%U https://ieeexplore.ieee.org/document/9181026/
%X In this paper, we present a CMOS-based miniaturized magnetic resonance (MR) system for magnetic field and trajectory mapping incorporating an electromagnetic interference (EMI) robust optical link. The system consists of a custom-designed, CMOS-based active NMR field probe, a custom-designed, single-bit ΣΔ modulator and a commercial optical link. The low-IF architecture of the transceiver ASIC, reduces the required bandwidth in the digitizer to a few hundred kilohertz, enabling the use of a single-bit ΣΔ modulator, whose high frequency, one bit data stream is ideally suited for feeding the following optical link. The custom ΣΔ modulator uses a third order loop filter and employs a 12-tap FIR DAC to increase its robustness against clock jitter. It is manufactured in a 0.18 μm CMOS technology and achieves an SNDR of 72.19 dB over a Nyquist bandwidth of 800 kHz. In the proposed setup, the 1-bit output stream of the ΣΔ modulator directly feeds the driver of a commercial optical fiber link to transmit the NMR data from inside the NMR magnet to the remotely located digital signal processing unit with a very high robustness against EMI. In-situ NMR experiments with a 1.45 T benchtop magnet using a silicone sample demonstrate the very good performance of the overall system, achieving a frequency resolution of 12.6 Hz or 200 ppb in the estimation of the sample's NMR resonance frequency. This corresponds to an effective magnetic field resolution of 290 nT.
@inproceedings{9181026,
abstract = {In this paper, we present a CMOS-based miniaturized magnetic resonance (MR) system for magnetic field and trajectory mapping incorporating an electromagnetic interference (EMI) robust optical link. The system consists of a custom-designed, CMOS-based active NMR field probe, a custom-designed, single-bit ΣΔ modulator and a commercial optical link. The low-IF architecture of the transceiver ASIC, reduces the required bandwidth in the digitizer to a few hundred kilohertz, enabling the use of a single-bit ΣΔ modulator, whose high frequency, one bit data stream is ideally suited for feeding the following optical link. The custom ΣΔ modulator uses a third order loop filter and employs a 12-tap FIR DAC to increase its robustness against clock jitter. It is manufactured in a 0.18 μm CMOS technology and achieves an SNDR of 72.19 dB over a Nyquist bandwidth of 800 kHz. In the proposed setup, the 1-bit output stream of the ΣΔ modulator directly feeds the driver of a commercial optical fiber link to transmit the NMR data from inside the NMR magnet to the remotely located digital signal processing unit with a very high robustness against EMI. In-situ NMR experiments with a 1.45 T benchtop magnet using a silicone sample demonstrate the very good performance of the overall system, achieving a frequency resolution of 12.6 Hz or 200 ppb in the estimation of the sample's NMR resonance frequency. This corresponds to an effective magnetic field resolution of 290 nT.},
added-at = {2020-10-12T12:57:07.000+0200},
author = {{Zhao}, J. and {Mohamed}, A. and {Anders}, J.},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/268d19032c1e4c5561f2a6846e1c8c889/iis},
booktitle = {2020 IEEE International Symposium on Circuits and Systems (ISCAS)},
doi = {10.1109/ISCAS45731.2020.9181026},
interhash = {823289576e59868a6a03f9d96ed71008},
intrahash = {68d19032c1e4c5561f2a6846e1c8c889},
issn = {2158-1525},
keywords = {myown iis from:aymanmohamed},
month = oct,
pages = {1-5},
timestamp = {2020-10-12T10:57:07.000+0200},
title = {An Active CMOS NMR Field Probe with Custom Transceiver and ΣΔ Modulator ASICs and an Optical Link},
url = {https://ieeexplore.ieee.org/document/9181026/},
year = 2020
}
