Autonomously Adaptable Wireless Power Charging System

In Phase I Busek evaluated a wireless power transfer (WPT) system to efficiently charge soldier mounted battery powered devices. Our WPT system is based on novel RF power amplifier topology which autonomously tunes its frequency to match the resonant frequency of a coupled load. The system operated very efficiently, reaching measured power transfer efficiency of 90%. Phase I also demonstrated the effectiveness of a shield for blocking fringing magnetic fields which increases system efficiency while minimizing deleterious impact of time varying electromagnetic field on the soldier(s). In Phase II optimization of this circuit and the shield design will be performed. Modeling and testing will be performed to verify safe operating conditions. A system design definition task will be performed to establish a set a reference design requirements. The system design definition will be augmented by modeling to predict the performance of the WPT system as functions of relevant parameters. Toward the end of Phase II the WPT subsystems will be integrated into a functional bench prototype and fully characterized. Following prototype testing, a high fidelity engineering model will be developed and rigorously tested in a representative operational environment. Prototype receiver/transmitter units will be delivered to the Army for field testing.