An Adaptive Reconfigurable Active Voltage Doubler/Rectifier for Extended-Range Inductive Power Transmission

Area of Science:

• Electrical Engineering
• Integrated Circuit Design
• Wireless Power Transfer

Background:

• Passive voltage doublers (VD) and rectifiers (REC) often suffer from high dropout voltage and lower power conversion efficiency (PCE).
• Existing inductive power transmission systems have limitations in range due to fixed circuit topologies.
• Robust wireless power transmission requires efficient energy conversion and adaptability to varying conditions.

Purpose of the Study:

• To develop an adaptive reconfigurable active voltage doubler/rectifier (VD/REC) circuit.
• To enhance the robustness and range of inductive power transmission.
• To improve power conversion efficiency (PCE) and reduce dropout voltage compared to passive counterparts.

Main Methods:

• Designed and fabricated an adaptive VD/REC in a standard 0.5-µm 3-metal 2-poly CMOS process.
• Implemented offset-controlled high-speed comparators to drive rectifying switches at optimal times.
• Enabled adaptive topology switching between VD and REC modes based on output voltage sensing.

Main Results:

• The fabricated active VD/REC achieved significantly lower dropout voltage and higher PCE than passive circuits.
• Extended inductive power transmission range by 33% in relative coil distance and 41.5% in relative coil orientation.
• Achieved measured PCEs of 70% (VD mode) and 77% (REC mode) at 13.56 MHz with a 500-Ω load.

Conclusions:

• The adaptive reconfigurable active VD/REC offers superior performance for wireless power transmission.
• The circuit's ability to switch topologies enhances robustness and extends operational range.
• This CMOS-based solution provides a significant advancement in efficient and reliable inductive power transfer.