Voltage-boosting wireless power delivery system with fast load tracker by ΔΣ-modulated sub-harmonic resonant switching

Recently, many applications have emerged that use wireless power delivery technology. A new standard “Qi” [1] has been established for battery operated portable devices. The rechargeable battery acts as a power buffer and shields the rapid load variation. Therefore, the requirement of the response to load variation is not so stringent and time constant of the power control loop is longer than several tens of milliseconds. Several hundred kHz band is chosen for switching frequency to reduce the power loss and frequency modulation (FM) [2] or pulse-width modulation (PWM) [3] are used for power control because of their relaxed in-band spurious emission regulation.

[1]  Aiguo Patrick Hu,et al.  A Frequency Control Method for Regulating Wireless Power to Implantable Devices , 2008, IEEE Transactions on Biomedical Circuits and Systems.

[2]  Dongyuan Qiu,et al.  Study on frequency-tracking wireless power transfer system by resonant coupling , 2009, 2009 IEEE 6th International Power Electronics and Motion Control Conference.

[3]  Tadahiro Kuroda,et al.  1W 3.3V-to-16.3V boosting wireless power transfer circuits with vector summing power controller , 2011, IEEE Asian Solid-State Circuits Conference 2011.