Original scientific paper
https://doi.org/10.24138/jcomss-2025-0221
Slot-Enhanced Dual-Band Microstrip Ring Resonator Sensor for Non-Invasive Blood Glucose Measurement
Amjad Hussein Yousif
; University of Mosul, Mosul, Iraq
Saad Wasmi Osman Luhaib
; University of Mosul, Mosul, Iraq
*
Mohammed Younis Thanoun
; University of Mosul, Mosul, Iraq
* Corresponding author.
Abstract
This paper presents a new solt-enhanced dual-band
microstrip ring resonator for non-invasive glucose estimation
fabricated on FR-4. The slot placed beneath the sample to
increase electric-field participation in the sensing volume. The
structure supports two well-separated resonances near 2.4 GHz
and 5 GHz whose minima shift monotonically with glucose concentration
across 0–400 mg/dL, enabling linear inverse modeling
and ratio metric features that mitigate common-mode drift.
Five regression models were evaluated—single-band linear and
quadratic (for each band) and a dual-band linear mapping using
(f1,f2)—on a dataset generated with a Debye-based permittivity
parameterization; the dual-band linear model delivered the best
accuracy–robustness trade-off with training MAE = 8.53 mg/dL,
RMSE = 10.13 mg/dL, R2=0.9938, and leave-one-out crossvalidation
R2=0.9881, MAE = 12.23 mg/dL, RMSE = 14.11
mg/dL, whereas a quadratic dual-band alternative over fit.
Frequency-detection resolution and normalized sensitivity are
reported for both bands to support fair comparison among
configurations, and the slot-enhanced layout achieves higher
sensitivity without sacrificing compactness, indicating a practical
path toward calibration-efficient bio sensing.
Keywords
Dual-Band Resonator; FR-4; Microwave Biosensing; Non-Invasive Glucose; Slot-Enhanced Coupling
Hrčak ID:
348547
URI
Publication date:
31.3.2026.
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