Gesture Detection Based on Antenna Impedance Measurements

A wireless earbud comprising:

• an antenna having a first arm and a second arm that is longer than the first arm;
• a transmission line path coupled to the antenna;
• a signal coupler disposed along the transmission line path;
• and
• one or more processors configured to
• use the signal coupler to measure a first impedance of the first arm and a second impedance of the second arm, and
• detect a gesture based on a change in the first impedance over time and a change in the second impedance over time.

A method of operating an electronic device comprising:

• transmitting, using one or more radios, transmission blocks according to a communications schedule, the transmission blocks being separated in time by gaps;
• transmitting, using an antenna, unscheduled transmission blocks during at least one of the gaps;
• measuring, using a signal coupler, an impedance of the antenna based on the unscheduled transmission blocks;
• detecting, using one or more processors, a gesture based on a change in the impedance over time;
• and
• transmitting, to an external device that is wirelessly paired with the electronic device, a signal based on the detected gesture.