Design of improved antenna with the slotted periodic structures for SAR reduction in body-worn communication device

摘要

This paper proposes an improved antenna with the slotted periodic structures for specific absorption rate (SAR) reduction in a body-worn communication device at a wideband code division multiple access (WCDMA) band. The slotted periodic structures are comprised of a squared unit cell with slots, dielectric board and ground. This periodic structure is a kind of an Artificial Magnetic Conductor (AMC) structure which acts as a perfect magnetic conductor (PMC). This structure can control the radiation pattern of the antenna. Since body-worn communication devices are used near the human body, a health problem originated from electromagnetic waves generated by communication devices is an important issue. The proposed antenna with a slotted periodic structure can change the radiation pattern and the electromagnetic fields toward the human body are reduced. Thus, this structure reduces the SAR value and is capable of protect the human body. To improve the antenna for the SAR reduction, the antenna position is changed. All structures are worked on the human body phantom. The S-parameters, radiation patterns and SAR values of the designed structures are presented. The results present a 46% improvement of SAR reduction characteristic at center frequency. Thus, the human body can be protected from electromagnetic waves using the proposed structure.