Hemispherical Coaxial Probe for Deep Breast Tissue Dielectric Characterization

Fernandez-Aranzamendi E.; Escobedo-Segovia F.; Castillo-Aranibar P.; Castillo E.S.R.; Amor-Martin A.; Segovia-Vargas D. · IEEE Transactions on Antennas and Propagation (2026) · DOI: 10.1109/tap.2026.3733445

Resumen

A hemispherical-tip coaxial probe for microwave dielectric characterization of deep breast tissue in the 1–8 GHz frequency range is presented in this paper. The proposed geometry improves probe–tissue coupling (lower pressure and fewer microgaps) and increases the effective sensing volume in these multilayer scenarios (skin–fat–gland–tumor), while maintaining a stable resonant response. The methodology integrates electromagnetic and equivalent-circuit modeling, materials selection, open-short-load (OSL) calibration with thermal/mechanical control, and an uncertainty quantification analysis. Serving as a pre-clinical validation, the methodology combines simulations, reference liquids, and tissue-mimicking phantoms. Results show improved coupling, enhanced spectral stability, and strong agreement between simulation and experiment. Overall, the hemispherical probe enables the stable dielectric characterization over an effective sensing depth of up to 7 mm in layered breast phantoms, while reducing the contact pressure required for repeatable coupling and avoiding tissue penetration.

Instituciones: Universidad Católica San Pablo