search query: @keyword base station antenna / total: 1
reference: 1 / 1
« previous | next »
Author:Laakso, Ilkka
Title:FDTD Method in Assessment of Human Exposure to Base Station Radiation
FDTD-menetelmä tukiasema-antennin säteilylle altistumisen arvioinnissa
Publication type:Master's thesis
Publication year:2007
Pages:viii + 92      Language:   eng
Department/School:Sähkö- ja tietoliikennetekniikan osasto
Main subject:Sähkömagnetiikka   (S-96)
Supervisor:Nikoskinen, Keijo
Instructor:Uusitupa, Tero
Electronic version URL: http://urn.fi/urn:nbn:fi:tkk-009677
OEVS:
Electronic archive copy is available via Aalto Thesis Database.
Instructions

Reading digital theses in the closed network of the Aalto University Harald Herlin Learning Centre

In the closed network of Learning Centre you can read digital and digitized theses not available in the open network.

The Learning Centre contact details and opening hours: https://learningcentre.aalto.fi/en/harald-herlin-learning-centre/

You can read theses on the Learning Centre customer computers, which are available on all floors.

Logging on to the customer computers

  • Aalto University staff members log on to the customer computer using the Aalto username and password.
  • Other customers log on using a shared username and password.

Opening a thesis

  • On the desktop of the customer computers, you will find an icon titled:

    Aalto Thesis Database

  • Click on the icon to search for and open the thesis you are looking for from Aaltodoc database. You can find the thesis file by clicking the link on the OEV or OEVS field.

Reading the thesis

  • You can either print the thesis or read it on the customer computer screen.
  • You cannot save the thesis file on a flash drive or email it.
  • You cannot copy text or images from the file.
  • You cannot edit the file.

Printing the thesis

  • You can print the thesis for your personal study or research use.
  • Aalto University students and staff members may print black-and-white prints on the PrintingPoint devices when using the computer with personal Aalto username and password. Color printing is possible using the printer u90203-psc3, which is located near the customer service. Color printing is subject to a charge to Aalto University students and staff members.
  • Other customers can use the printer u90203-psc3. All printing is subject to a charge to non-University members.
Location:P1 Ark S80     | Archive
Keywords:FDTD
specific absorption rate
base station antenna
absorbing boundary conditions
SAR
tukiasema-antenni
absorboivat reunaehdot
Abstract (eng):FDTD is an explicit finite-difference method that solves the Maxwell's equations numerically in the time domain.
The objective of this thesis is to investigate the application of the FDTD method in the assessment of the human exposure to base station radiation.
At radio frequencies, the exposure to electromagnetic radiation is given in terms of SAR values (specific absorption rate).
SAR describes the power loss inside the tissues, and is linked to the possible adverse health effects of radiation.

The motivation for this study lies in the standardization regarding exposure to base-station antennas.
At radio frequencies, FDTD is the most used method in the problems involving full human body models, and it is thus of great importance to study how reliably the SAR values are assessed in FDTD, and which factors affect the accuracy of the results.

The emphasis of this thesis is on the methods which are needed in the FDTD-SAR calculations and their uncertainties.
How the resolution of the FDTD discretization affects the SAR values is of particular interest.
Among other things, material modeling in FDTD and the applicability of absorbing boundary conditions in SAR calculations are studied in detail.
Naturally, the final results are affected by how the SAR values actually are calculated.
Several different methods for SAR calculation are presented in this work, and their effects on the results are studied.
Abstract (fin):FDTD on eksplisiittinen aika-alueen differenssimenetelmä, joka ratkaisee Maxwellin yhtälöt numeerisesti.
Tämän diplomityön tarkoituksena on selvittää FDTD-menetelmän soveltamista tukiasema-antennin säteilylle altistumisen arvioimisessa.
Radiotaajuuksilla sähkömagneettiselle säteilylle altistumista mitataan niin sanottujen SAR-arvojen (specific absorption rate) kautta, jotka kertovat sähkömagneettisesta häviötehosta kudoksissa ja ovat yhteydessä säteilyn mahdollisiin haitallisiin terveysvaikutuksiin.

Motivaatio tälle tutkimukselle on tukiasema-antenneihin liittyvässä standardoinnissa.
Radioaaltoalueen koko kehon tehtävissä FDTD-menetelmä on yleisesti käytetyin menetelmä, ja on tärkeää tietää, kuinka luotettavasti säteilyannoksia saadaan arvioitua, ja mitkä tekijät vaikuttavat tulosten tarkkuuteen.

Työn pääpaino on FDTD SAR-laskennassa tarvittavissa menetelmissä, niiden epävarmuuksissa ja virhetekijöissä.
Erityisenä tutkimuskohteena on FDTD:n diskretoinnin resoluution vaikutus SAR-arvoihin.
Lisäksi paneudutaan muun muassa materiaalien mallintamiseen FDTD:ssä sekä absorboivien reunaehtojen toimivuuteen SAR-laskennassa.
Lopputulosten kannalta on myös tärkeää, miten SAR-arvot on itse asiassa laskettu.
Työssä esitelläänkin joitakin vaihtoehtoisia tapoja laskea SAR-arvoja, ja tutkitaan näiden vaikutusta tuloksiin.
ED:2007-08-22
INSSI record number: 34467
+ add basket
« previous | next »
INSSI