The Finite Difference Time Domain MethodFDTDHaythem H. abdullah ERI, Electronics Research Institute,Microwave Engineering Dept.

**Objective

Analysis of the FDTD with regard to its application in studying the effect of the electromagnetic effect on the human health

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**Description of the FDTD MethodThe FDTD technique proceeds by segmenting the structure and the surrounding space into a three-dimensional mesh composed of a number of rectangular unit cells. The following figure shows the spatial locations of both the E and H components

**Positions of various field components. The E components are in the middle of the edges and the H components are in the center of the faces.

**Description of the FDTD MethodIt is based on numerically solving Maxwells curl equations.The time and space derivatives are approximated using finite difference approximationsThe E and H fields are evaluated iteratively at alternative half-time steps

**Description of the FDTD MethodMaxwells curl equations are

**Description of the FDTD Method

**Description of the FDTD MethodThe finite difference scheme will be central difference in time and spaceThe E component in the x-direction

**Description of the FDTD MethodThe magnetic field component in the y-direction

**Description of the FDTD MethodWhere

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**Absorbing Boundary ConditionSince the spatial computational domain can be considered unbounded, so the need for absorbing boundary condition (ABC) is an urgent demand.No computer can store an unlimited amount of data

**Absorbing Boundary Condition

ABC is used to simulate the extension of the computational domain to infinity.The lack of ABC results in a computational error due to the reflection from the truncated domain, see the following figure

**Absorbing Boundary ConditionTwo-dimensional Cartesian computational domain showing the outer domain boundary at which an ABC is implemented to simulate the extension of the grid to infinity.

**Why the need for parallel processingThe serial code needs some times, days or even months for large problem size

**Why this application has been developedThis application will be used as a safety guideline for the mobile companies to use a safe base station and handset units

**Who use this applicationThe microwave engineers and researchers

**Which input your application need to runThe input is a data file that includes the human body model data

**How many jobs you should need to submit (average).Almost it is one job

**Which output your application produceA data file that have the SAR values at different planes in the human body

**How much is the execution time of your job (average).The serial running time in the human head model may exceed 7 hoursThe parallel code time is dependent on the obtained speed up

**Who writes the code.I write the serial codeThe parallel code is done by Eng. Maha Eldespoki

**Do you use any commercial application (as Matlab)?.I write the serial code using c++

**Do you use any commercial application (as Matlab)?.I write the serial code using c++

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