Research Article
Spinning Current Technique for Graphene-Based Hall Sensors
Vinit Vithalrai Shenvi
,
Ashutosh Sharma*
Issue:
Volume 13, Issue 1, June 2025
Pages:
1-11
Received:
2 February 2025
Accepted:
21 February 2025
Published:
28 February 2025
Abstract: Spinning Current Technique (SCT) is a pioneering solution to counter the inherent offset voltage challenge in Hall plates, crucial devices for magnetic field detection. SCT dynamically eliminates the offset, enabling precise measurement of magnetic field magnitudes. Successfully applied to a symmetrical Hall device, SCT involves the controlled rotation of terminals to preserve the induced Hall voltage polarity while reversing the offset voltage polarity, offering a groundbreaking resolution. Leveraging the distinctive properties of Hall plates, the study introduces a specifically designed SCT circuit for a chosen Hall plate, demonstrating remarkable accuracy in simulations. The paper proposes advancing the SCT for Graphene-based Hall sensors, capitalizing on Graphene's superior characteristics for heightened sensitivity, linearity, and temperature stability. The primary objective is the integration of SCT into Graphene Hall Sensors, potentially resulting in cost-effective, highly sensitive magnetic sensors. The adaptability of Hall plates allows for testing on various plates to evaluate performance. The paper underscores critical parameters such as Hall voltage, offset voltage, power supply ratings, and temperature considerations. While existing products target similar goals, the uniqueness of this study lies in unexplored terrain—implementing SCT on Graphene Hall plates. The intended users are manufacturers of commercial Hall sensors, applicable in diverse fields such as current measurement, magnetometry, positional sensing, motion tracking, and geomagnetic field measurement.
Abstract: Spinning Current Technique (SCT) is a pioneering solution to counter the inherent offset voltage challenge in Hall plates, crucial devices for magnetic field detection. SCT dynamically eliminates the offset, enabling precise measurement of magnetic field magnitudes. Successfully applied to a symmetrical Hall device, SCT involves the controlled rota...
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Research Article
Adaptive Modulation and Coding Control Based on Human Body Channel Characteristics Under Different WBAN Scenarios
Dairoku Muramatsu*
Issue:
Volume 13, Issue 1, June 2025
Pages:
12-21
Received:
6 May 2025
Accepted:
20 May 2025
Published:
20 June 2025
Abstract: Wireless Body Area Network (WBAN) enables continuous health monitoring by interconnecting wearable and implantable sensors, but their links suffer from strongly scenario-dependent human-body propagation effects that conventional physical-layer (PHY) designs do not address. Most prior studies assess limited WBAN links, so a unified strategy that spans all scenarios remains missing. This work presents a comprehensive adaptation framework across all three IEEE 802.15.6ma communication scenarios with minimal feedback overhead, ensuring consistent performance under diverse channel conditions. This study aims to maximize WBAN throughput by adaptively selecting the modulation and coding scheme according to channel characteristics unique to three IEEE 802.15.6ma communication scenarios: 21 MHz on-body, 400 MHz in-body, and 2.4 GHz off-body. By leveraging finite-difference time-domain analysis on a detailed whole-body voxel model combined with a compact hybrid antenna, we capture realistic, wideband channel responses that reflect both on-skin and implanted device environments. Wide-band channel responses were first obtained with finite-difference time-domain analysis of the whole-body voxel model combined with a compact hybrid antenna that integrates galvanic electrodes and patch radiators. The channel responses were fed into link-level simulations covering BPSK, QPSK, GMSK and 16-QAM, with and without BCH (63, 51) coding. QPSK was most efficient at mid-range SNR, whereas coded 16-QAM became superior once Eb/N0 exceeded roughly 10 dB, boosting off-body throughput by up to 35%. Applying simple Eb/N0 thresholds (≈ 6-13 dB) to switch between QPSK and coded 16-QAM almost doubled the data rate versus a fixed conservative scheme while still meeting the error-free requirement of medical telemetry. These results highlight the practical benefits of our adaptive control approach for real-world WBAN deployments, including reduced power consumption and simplified transceiver design.
Abstract: Wireless Body Area Network (WBAN) enables continuous health monitoring by interconnecting wearable and implantable sensors, but their links suffer from strongly scenario-dependent human-body propagation effects that conventional physical-layer (PHY) designs do not address. Most prior studies assess limited WBAN links, so a unified strategy that spa...
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