Implantable medical device structures including recharge and/or telemetry coil

An implantable medical device comprising:

• a hermetically sealed housing that is configured to enclose internal components, the internal components including:
• processing circuitry configured to at least one of control stimulation circuitry to deliver electrical stimulation using one or more leads received by the housing or control sensing circuitry to sense electrical signals using one or more leads received by the housing,
• telemetry circuitry, and
• a rechargeable power source, and
• a coil configured to at least one of receive energy to recharge the rechargeable power source or receive and/or transmit signals for wireless telemetry with another device,
• wherein the implantable medical device is configured to mount to a cranium of a patient, and wherein the coil is wound in a tapered configuration such that the tapered coil has a narrowed portion defining a first coil height that is less than a second coil height of another portion of the tapered coil.