Design of Button Antenna for Wearable Applications in Bluetooth Band

A button antenna is proposed in Bluetooth frequency band. The button antenna is composed of one radiating patch at the top, one copper ground plane on the bottom, the coaxial cable, two shorting pins and the textile substrate. Two shorting pins symmetrically placed about the feed are close to the coaxial cable so the antenna looks like a button. The results are simulated both without and with a human body, and it’s shown that the button antenna can cover the whole Bluetooth frequency band in both conditions. The simulated radiation efficiency is 87.48% in free space and 56.48% with human body. The radiation pattern of button antenna is omnidirectional in the horizontal direction. The calculated SAR values of both without and with a human body meet the standards.