Author(s)

Y. Hirayama & E. Kita

Abstract

This paper describes the application of Trefftz method to the temperature rise in a human skin exposed to a radiation from a cellular phone. A governing equation is given as Poisson equation. An inhomogeneous term of the equation is approximated with a polynomial function in Cartesian coordinates. The use of the approximated term transforms the original boundary-value problem to that governed with a homogeneous differential equation. The transformed problem can be solved by the traditional Trefftz formulation. Firstly, the present method is applied to a simple numerical example in order to confirm the formulation. The temperature rise in a skin exposed to a radiation is considered as a second example. Keywords: Trefftz method, poisson equation, polynomial function. 1 Introduction There has been an increasing public concern regarding the possible health effects of human exposure to an electromagnetic radiation. In Japan, there are four cellular phone carrier companies; NTT Docomo, au, Softbank (vodafone) and Willcome. They provide different types of cellular phone services. NTT Docomo, au and Softbank (vodafone) provides Code Division Multiple Access (CDMA)-type phones and Willcome Personal Handy-phone System (PHS)-type ones. The CDMA-type phones are so-called 3G-cellular phones, which are used widely around the world. The PHS-type phones operate in the 1880–1930 MHz frequency band, which are used mainly in Japan, China, Taiwan and some other Asian countries. Since carrier companies operate different services, their health effects are also dissimilar. In this paper, we will focus on the temperature rise in a human skin exposed to the radiation. The hazardous electromagnetic field levels can be quantified analyzing the thermal response of the human body exposed to the radiation [1, 2].

Keywords

Trefftz method, poisson equation, polynomial function.