Novel Multiband Metal-Rimmed Antenna for Wearable Applications

A novel multiband antenna with an unbroken metal rim for wearableapplications is presented. In order to achieve a wideband behavior, minimizing at thesame time the size of the clearance area on the antenna ground plane, a novel feedingstructure is proposed. This is achieved by connecting the metal rim to the groundplane thus allowing generating one lower-frequency resonance without occupying alarge area. An additional resonance is then obtained using a suitable shorting patch. Inthis way, the proposed antenna presents a broadband behavior, while the width of theclearance area on the ground plane is of only 2 mm. The antenna performances infree-space and on a human phantom simulating a human body are analyzed by meansof numerical simulations. Finally, the specific absorption rate (SAR) is analyzed toestablish the antenna reliability in wearable applications. The experimental resultsdemonstrate superior and stable performances of the metal-rimmed antenna when it isemployed in wearable applications.