Time dependence of dielectric properties of human body phantoms

K. Fukunaga1, S. Watanabe1, K. Wake1, Y. Yamanaka1
1Communications Research Laboratories, Koganei, Tokyo, Japan

Tóm tắt

Standard methods for measurement of the specific absorption rate (SAR) including recipes of tissue-equivalent dielectric liquid have been discussed by international standard organisations in order to evaluate mobile telecommunication equipment. Standards, and draft documents of standards recommend glycol type liquids as issue-equivalent liquids for frequencies above 1 GHz. Although the amounts of the ingredients are specified in recipes, possible difficulties such as stability of dielectric properties are not clearly described. We measured the time dependence of the relative permittivities and conductivities of glycol-based dielectric liquids, and discussed their influence on SAR. The experimental results suggest that relative permittivities decreased with time and conductivities were almost constant. SAR, however, was not affected significantly by the change in relative permittivities.

Từ khóa

#Humans #Imaging phantoms #Permittivity #Measurement standards #Telecommunication standards #Dielectric measurements #Dielectric liquids #Conductivity #Specific absorption rate #Frequency

Tài liệu tham khảo

10.1109/22.884187 gabriel, 1996, Compilation of the dielectric properties of body tissues at RF and microwave frequencies, Brooks Air Force Technical Report AUOE-TR-1996-0037 10.1109/22.539947 10.1109/22.539946 watanabe, 2001, Specific Absorption Rates in Head Phantoms of Different Shape and Size for Cellular Telephone Use, Asia-pacific Radio Science Conference, 272 2001, Product standard to demonstrate the compliance of mobile phones with the basic restrictions related to human exposure ti electromagnetic fields (300 MHz-3GHz), Ref No EN 50360 2001 2001, Recommended Practice for Determining the Peak Spatial-Average Specific Absorption Rate (SAR) in the Human Body Due to Wireless Communications Devices: Experimental Techniques, Draft 6 5