Battery coupling impact on the antenna efficiency in a small wearable device

Wearable electronics is often challenged by the extremely reduced space available to the antenna design. This study assesses the impact that the coupling to a large battery has on a small antenna for wearable devices. The coupling mechanism and its potential risks for the Electromagnetic Compatibility (EMC) performance are discussed in detail. Once the battery is placed within an electronic device, it is seen that one of the main performance parameters, i.e., the antenna radiation efficiency, may drop up to 1.2 dB depending on the battery size.