An optimized antenna for mobile phones

IMST is investigating the user's influence on the radiation characteristics of mobile phones. If a handset is in a typical user position, the radiated power is strongly decreased because of the losses in the user's body. This effect depends on the kind of antenna that is used for the mobile. Several concepts of optimized handset antennas have been developed. These antennas have a better overall efficiency, meaning that the percentage of the power absorbed by the user's body is minimized. The advantages of these concepts are high radiated power, low SAR values (specific absorption rate) and a longer standby time in the handset. One of these concepts, the EID antenna, is presented. The EID antenna has been simulated and realized at 450 MHz and at 925 MHz.