Local SAR Estimate and Incident Power Density
Estimate local specific absorption rate (SAR) from a known RMS electric field in a homogeneous material, its conductivity and mass density. A separate calculation converts an incident RMS electric field into power density for an ideal free-space plane wave in the far field.
These simplified models are not measurements or compliance assessments of a real device. They do not include coupling, frequency-dependent material properties, spatial or time averaging, device geometry, phantoms or measurement uncertainty.
Local SAR Estimate
Model equations:
SAR = σ × Elocal² / ρ
RMS field in a homogeneous material; point value without spatial or time averaging.
Incident Power Density
Model equations:
S = Eincident² / Z₀
Ideal free-space plane wave in the far field; Z₀ ≈ 377 Ω.
Use these calculations to:
Estimate the magnitude of local SAR from a known or simulated local electric field in a homogeneous material.
Explore how electric field, conductivity and mass density affect the local SAR estimate.
Convert incident far-field strength into power density for an ideal free-space plane wave.
Device SAR and regulatory compliance require the applicable standardized measurement or assessment procedure.
Author: IBL-Editors Team
Technical Review: Andreas Bender - Deputy Managing Director | IBL-Lab GmbH Give feedback on this article