Wireless Powering for Glass-Laminated Functionalities

This paper introduces a safe, high efficiency, small size wireless power transfer (WPT) system with extremely thin power receiver capable of supplying up to 30W electric DC power for lighting, display, sensing and communication functionalities inside glass laminates. When compared to the existing WPT systems such as those based on the Qi low power specification of the Wireless Power Consortium, the main differences of the technical implementation for better applicability to glass laminate applications are a novel self-regulating antenna tuning solution and relatively high (6.78 MHz) operation frequency. The self-regulating antenna tuning solution keeps the receiver output voltage nearly stable and maintains high efficiency by keeping the antennas in resonance with variable loading of the power receiver. The WPT system is based on a class-D topology RF inverter at the power transmitter side. The safety of the WPT system to nearby humans and electrical devices is ensured by ferrite shielding of the antenna coupler. The performance of the WPT system has been evaluated by theoretical analysis, circuit simulations and a preliminary experimental system. The simulations show 57 % total DC-to-DC power transfer efficiency with the nominal 30 W receiver output power, which probably can be improved by refining the design of the RF inverter.