Abstract: A system of a power device and a portable device for wireless charging of a battery of the portable device. The power device includes an antenna to receive power adjustment information to increase or to decrease the power of the magnetic field emitted by the antenna of the power device and an antenna exposed to the magnetic field and connected via a matching stage to a rectifier stage. The portable device includes a voltage limiter, to limit the rectified antenna signal, and to provide an input voltage at an input pin of a charger IC. A charge voltage control stage is built to generate the power adjustment information for the power device to increase or to decrease the power of the magnetic field emitted by the antenna of the power device to steer the waste current within an upper limit and a lower limit.

Abstract: A system including a power device for wireless charging of a battery of a portable device, and the power device has an antenna to emit a magnetic field with a carrier frequency to power the portable device which includes an antenna exposed to the magnetic field and connected via a matching stage to a rectifier stage, to rectify an antenna signal, and the portable device comprises a charge stage, to sense and limit the rectified antenna signal. The portable device includes a detuning stage to change the resonance frequency of the antenna of the portable device and that the charge stage is configured to limit the input voltage (UI) for the charger IC by steering the detuning stage to detune the resonance frequency of the antenna of the portable device away from the carrier frequency of the magnetic field.