CONTACT-FREE INTERACTION WITH AN ELECTRONIC DEVICE

摘要

The present disclosure provides an electronic device configured to detect an object positioned at a distance. The electronic device includes a reference oscillator generating a reference signal having a reference frequency; and a first measurement oscillator coupled to a first antenna located at a first position of the electronic device. The first measurement oscillator generates a first measurement signal having a first measurement frequency corresponding to a distance of an object from the first antenna. The first antenna has a first antenna load corresponding to the distance of the object from the first antenna, and the first measurement frequency varies in dependence on the first antenna load. The electronic device also includes a comparator coupled to the reference oscillator and the first measurement oscillator which generates a comparator output including a difference between the reference frequency and the first measurement frequency which represents the distance of the object from the first antenna.