Mid-Range Wireless Power Transfer at 100 MHz Using Magnetically Coupled Loop-Gap Resonators

We describe efficient four-coil inductive power transfer (IPT) systems that operate at 100 MHz. The magnetically coupled transmitter and receiver were made from electrically small high- Q loop-gap resonators (LGRs). In contrast to the commonly used helical spiral resonators, LGR design has distinct advantage electric fields are strongly confined capacitive gap of resonator. With negligible fringing in surrounding space, IPT system is immune interference nearby dielectric objects, even when they close proximity and/or receiver. experimented with both cylindrical split-toroidal (TLGR) geometries. Although performed well under laboratory conditions, toroidal geometry additional magnetic flux weak everywhere except within bore space directly between Furthermore, we show TLGR can be operated efficiently a fixed frequency for wide range transmitter-receiver distances. experimental results complimented by 3-D finite-element simulations investigate electromagnetic field profiles surface current density distributions. Finally, demonstrate use our powers up 32 W discuss possible applications.