Abstract
This paper presents a novel millimeter-wave (mmWave) button antenna designed for off-body communication in Wireless Body Area Networks (WBANs). The proposed antenna comprises a circular patch incorporating multiple slots to optimize performance. The antenna's results were investigated in free space and the presence of denim fabric, with measurements conducted on the chest and hand positions. The simulated and measured results demonstrate a satisfactory impedance bandwidth encompassing the 28 GHz mmWave band in all scenarios, with a consistent gain of 6.10 dBi. The radiation patterns indicate minimal influence of the fabric material, and the antenna maintains its broadside radiation. The design's compactness, good matching, stable gain, and good radiation characteristics make it suitable for integration into clothing and other wearable devices.