Apple Inc.
Dielectric-loading detection apparatus

Abstract:

An apparatus for detecting worn and/or unworn status of a wearable host device includes one or more first antennas, a second antenna, and a radio-frequency (RF) circuit to measure a dielectric loading based on an RF isolation. The second antenna is placed within a portion of the wearable host device that is substantially in contact with the skin of a user, and the RF isolation is between at least one of the one or more first antennas and the second antenna.