Systems and methods for improving thermal performance of wireless power transfer systems

A wireless power transfer system for supplying power to an implantable medical device, comprising:

• a receive resonator;
• and
• a transmit resonator comprising:
• a core;
• a coil element disposed within a portion of the core;
• and
• a housing surrounding the core and the coil element, the housing comprising a metal plate forming a side of the housing that is opposite the receive resonator during operation of the wireless power transfer system, wherein an outer diameter of the metal plate is greater than an outer diameter of the core.

A transmit resonator for use in a wireless power transfer system for supplying power to an implantable medical device, the transmit resonator comprising:

• a core;
• a coil element disposed within a portion of the core;
• and
• a housing surrounding the core and the coil element, the housing comprising a metal plate forming a side of the housing, wherein a gap is defined between the housing and the core, wherein the gap is filled with a thermally conductive gap material.