A Novel Cellular Handset Design for an Enhanced Antenna Performance and a Reduced SAR in the Human Head

Abstract

This paper presents a novel cellular handset design with a bottom‐mounted short loaded‐whip antenna. This new handset design is modeled and simulated using a finite difference time‐domain (FDTD)‐based platform SEMCAD . The proposed handset is based on a current commercially available bar‐phone type with a curvature shape, keypad positioned above the screen, and top‐mounted antenna. The specific absorption rates (SARs) are determined computationally in the specific anthropomorphic mannequin (SAM) and anatomically correct model of a human head when exposed to the EM‐field radiation of the proposed cellular handset and the handset with top‐mounted antenna. The two cellular handsets are simulated to operate at both GSM standards, 900 MHz as well as 1800 MHz, having different antenna dimensions and intput power of 0.6 W and 0.125 W, respectively. The proposed human hand holding the two handset models is a semirealistic hand model consists of three tissues: skin, muscle, and bone. The simulations are conducted with handset positions based on the IEEE standard 1528‐2003. The results show that the proposed handset has a significant improvement of antenna efficiency when it is hand‐held close to head, as compared with the handset of top‐mounted antenna. Also, the results show that a significant reduction of the induced SAR in the human head‐tissues can be achieved with the proposed handset.