International Journal of Bioelectronics

Computational Modeling and Numerical Analysis of the Effects of Cell Phones at 1800 MHz Frequency

Abstract

A computational model of the human head, composed of brain, skull, and skin geometries, was developed to analyze thermal effects produced by mobile-phone electromagnetic radiation. A patch antenna operating at 833 MHz simulated the phone source. Finite Element Method (FEM) analysis determined the temperature distribution and specific absorption rate (SAR). Results showed elevated SAR and temperature near the antenna, validating FEM as a reliable approach to estimate localized exposure.

Keywords: Cell phone, Human head, Electromagnetic field, SAR, Finite Element Method (FEM).

Introduction

Cell phones emit radio-frequency (RF) waves, a type of non-ionizing electromagnetic radiation absorbed by nearby tissue. Growing mobile-phone use has raised concerns about potential biological effects. Governments regulate SAR — the maximum power absorbed by living tissue — with limits of 1.6 W/kg (USA) and 2 W/kg (EU). The study models RF exposure in a three-layer head (brain, skull, skin) to evaluate heat distribution from a typical handheld device.

Methodology

The human-head geometry was reconstructed from CT images and meshed for FEM computation. A patch antenna was positioned near the left side of the model, and both geometries were enclosed within an air domain for electromagnetic propagation. The study coupled Maxwell’s equations (via the Helmholtz formulation) with Pennes’ bioheat equation to compute electric-field, SAR, and temperature distributions.

Materials and Boundary Conditions

Dielectric and thermal properties for brain, skull, and skin were assigned per ITIS Foundation (2015): conductivity 1.23 S/m (brain), 0.136 S/m (skull), 0.845 S/m (skin); relative permittivity 49.9, 12.5, 41.8 respectively. Boundary conditions included perfect electric conductor for antenna surfaces and absorbing boundaries for open space. Thermal insulation was applied to outer head surfaces.

Results and Discussion

Initial temperature was set to 0 °C for numerical stability; an RF port excited the antenna with 45.5 V and 75 Ω load. Simulations revealed temperature increases localized to the antenna region (Fig. 7) and corresponding SAR hot spots (Fig. 8). Maximum SAR values exceeded regulatory limits due to the high input power used for simulation purposes.

Conclusions

The computational model demonstrates that numerical analysis is a valuable tool to estimate thermal effects from mobile-phone exposure. Simulated SAR peaks occurred near the antenna contact region. Although applied power was greater than real phones, the results highlight potential hot spots and guide future work using actual device emission levels.

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© 2015 International Journal of Bioelectronics (IJBIOE). Article licensed under CC BY 4.0.