Resource-Efficient FPGA-based I/Q-Demodulator Detects 0.0005 Modulation Index with 9.5 dB SNR for Converse ME Sensors

Research output: Contribution to book/Conference proceedings/Anthology/ReportConference contributionContributedpeer-review

Contributors

  • Cristopher McGuinness-Rodriguez - , Bilkent University (Author)
  • Johan Arbustini - , Kiel University (Author)
  • Pablo Mendoza-Ponce - , Bilkent University (Author)
  • Eric Elzenheimer - , Kiel University (Author)
  • Andrey Morales-Zamora - , Bilkent University (Author)
  • Michael Höft - , Kiel University (Author)
  • Robert Rieger - , Kiel University (Author)
  • Andreas Bahr - , Chair of Biomedical Electronics (Author)

Abstract

This paper presents the design and implementation of a resource-efficient FPGA-based system for real-time demodulating and processing signals of Converse-Magnetoelectric (C-ME) sensors. This particular ME sensor type, also known as electrically modulated ME sensors, combining a piezoelectric resonator with a magnetostrictive layer, generates a DoubleSideband Amplitude Modulation with Carrier signal when excited at their resonance frequency defined by the sensor dimension. We simulate the implementation of an in-phase and quadrature (I/Q)-Demodulation approach to address phase shift challenges arising from unsynchronized excitation sources. This enables accurate recovery of the magnetic signal from the sensor’s signal envelope. We designed the system using a CORDIC-based numerically controlled oscillator for flexible carrier frequency generation and a cascaded integrator-comb filter for efficient decimation and noise reduction. Resource-sharing techniques in FIR low-pass filtering and a non-restoration square root algorithm were employed to maximize FPGA resource efficiency. The final processing stage includes DC offset removal to ensure accurate magnetic signal recovery at baseband. Simulation results assuming an ideal C-ME signal after the Analog-to-Digital Converter confirms that the system accurately demodulates the desired to-be-measured signal with a modulation index of at least 0.0005, giving an output signal-to-noise ratio of 9.5 dB at a sampling frequency of 1 MSa/s. This modulation index corresponds to the detection limit (equals three times the estimated noise amplitude spectral density), considering the C-ME sensor’s ultra-low noise spectral density and the signal conditioning and quantization noise contributions. The resource efficiency of the design allows future integrations and optimization of digital signal processing algorithms for further signal-to-ratio enhancing performance.

Details

Original languageEnglish
Title of host publication2024 IEEE 42nd Central America and Panama Convention (CONCAPAN XLII)
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Number of pages6
ISBN (electronic)979-8-3503-6672-3
ISBN (print)979-8-3503-6673-0
Publication statusPublished - 29 Nov 2024
Peer-reviewedYes

Conference

Title2024 IEEE 42nd Central America and Panama Convention
Abbreviated titleCONCAPAN XLII
Conference number42
Duration27 - 29 November 2024
Website
LocationHotel Crowne Plaza San José, La Sabana
CitySan José
CountryCosta Rica

External IDs

ORCID /0000-0001-8012-6794/work/184006560
Scopus 105005839490

Keywords

Keywords

  • Amplitude Modulation (AM), CIC (Cascaded-Integrator-Comb-Filter) Filter, CORDIC, Demodulation, FIR Filter, FPGA, In-Phase and Quadrature (I/Q), Medical Real-Time Signal Processing, Numerically Controlled Oscillator (NCO)