A study on RF exposure setups and small antennas for mobile phone

Abstract

The swollen use of mobile telecommunication devices brought about apprehensions for potential risks from that they are always carried on human body whether it is working or waiting on. And the commissions FCC and ICNIRP have settled the recommended limitation of electromagnetic coupling level between devices and human body for guaranteeing public safety. In the similar context of risk assessment for RF exposure by mobile phone, PERFORM B was a project that addresses replications of in vitro and in vivo studies that were recommended by the WHO agenda. The half of this thesis was dedicated for describing how to design and evaluate the two different RF exposure prototypes used for this replication studies. Firstly, a wheel type small exposure setup which has been widely used in the biological effect studies was developed and evaluated. Secondly, a mainly head exposure setup for mice was introduced. The aim of this study was to develop plausible exposure setups which have the same or more exposure performances with rather tiny equipments scale. If we range over a part of RF absorption and risk assessment for living body, the latter half of this thesis was allowed for showing how successful radiation could be with small and embedded mobile phone antennas which are electrically and mechanically compatible for recent mobile phone use.

Firstly, a small antenna using a new magneto-dielectric carrier is proposed for the next mobile applications. With an intrinsic longer wave length and adjacent conventional communication channels of Cellular 800 (824-894 MHz), LTE handsets would be recommended to behave from 704 MHz to 894 MHz for US low band LTE services. If we need the GSM scheme with a single device, the system should drive an additional 136MHz and the total bandwidth comes to be 256MHz from 704MHz to 960MHz. Considering about 30% wide bandwidth, the antenna should increase its impedance capacitance for diverse wavelengths by novel design of the antenna radiator ...