Some embodiments of the disclosure may include a device for wirelessly powering an implant unit in a body of a subject from a location outside of the body of the subject, wherein the implant unit includes a secondary antenna for wirelessly receiving energy. The device may include a primary antenna configured to be located external to the body of the subject, a circuit electrically connected to the primary antenna, and at least one processor electrically connected to the primary antenna and the circuit. The at least one processor may determine a resonant frequency mismatch between a first resonant frequency associated with the primary antenna and a second resonant frequency associated with the secondary antenna associated with the implant unit； and apply an adjustment to at least one component of the circuit to cause a change in the first resonant frequency associated with the primary antenna and a reduction in the resonant frequency mismatch.
