Parth Patel

EECS Department, University of California, Berkeley

Technical Report No. UCB/EECS-2022-176

July 26, 2022

http://www2.eecs.berkeley.edu/Pubs/TechRpts/2022/EECS-2022-176.pdf

Although Magnetic Resonance Imaging(MRI) has changed the world of medicine by providing a non-intrusive method of viewing the human anatomy, its implementation remains bulky and power hungry. The coaxial cables that it uses are oftentimes victims of electromagnetic interference and noise. Furthermore, coaxial cables are unable to transmit data at long distances so most computation must be done locally. Resonant ring resonators(RRM) are an emerging technology that could remove the drawbacks of traditional coaxial cables by providing a low interference and long distance data transmission method. As promising as this sounds, RRMs currently suffer from a low spur free dynamic range(SFDR) which greatly limits their practical usage in various applications, including MRI. One way of tackling this issue is by making the response of the ring resonator more linear through negative feedback. This thesis will cover the basic background of what RRMs are, a description of the circuits and feedback loop used to linearize its response, and experiments carried out to measure improvements in SFDR, bandwidth, etc. Additionally, this project report will serve as a timeline of progress made over the course of the project, from high level simulations to circuit level simulations to finally building out the feedback loop in physical hardware. Ultimately the TIA was fully built and was able to convert photocurrent from the ring drop port to a measurable voltage output.

Advisors: Vladimir Stojanovic

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BibTeX citation:

@mastersthesis{Patel:EECS-2022-176,
    Author= {Patel, Parth},
    Title= {Building a Ring Resonator Feedback Loop},
    School= {EECS Department, University of California, Berkeley},
    Year= {2022},
    Month= {Jul},
    Url= {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2022/EECS-2022-176.html},
    Number= {UCB/EECS-2022-176},
    Abstract= {Although Magnetic Resonance Imaging(MRI) has changed the world of medicine by providing a non-intrusive method of viewing the human anatomy, its implementation remains bulky and power hungry. The coaxial cables that it uses are oftentimes victims of electromagnetic interference and noise. Furthermore, coaxial cables are unable to transmit data at long distances so most computation must be done locally. Resonant ring resonators(RRM) are an emerging technology that could remove the drawbacks of traditional coaxial cables by providing a low interference and long distance data transmission method. As promising as this sounds, RRMs currently suffer from a low spur free dynamic range(SFDR) which greatly limits their practical usage in various applications, including MRI. One way of tackling this issue is by making the response of the ring resonator more linear through negative feedback. This thesis will cover the basic background of what RRMs are, a description of the circuits and feedback loop used to linearize its response, and experiments carried out to measure improvements in SFDR, bandwidth, etc. Additionally, this project report will serve as a timeline of progress made over the course of the project, from high level simulations to circuit level simulations to finally building out the feedback loop in physical hardware. Ultimately the TIA was fully built and was able to convert photocurrent from the ring drop port to a measurable voltage output.},
}

EndNote citation:

%0 Thesis
%A Patel, Parth 
%T Building a Ring Resonator Feedback Loop
%I EECS Department, University of California, Berkeley
%D 2022
%8 July 26
%@ UCB/EECS-2022-176
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2022/EECS-2022-176.html
%F Patel:EECS-2022-176