Disclosed herein are example configurations of implantable units of implantable medical devices such as hearing devices. An example implantable hearing device includes a housing having a posterior side and an anterior side, with the anterior side being formed such that an inner edge of the anterior side defines an aperture. The housing includes an electrical feedthrough, a transceiver, and an antenna element. The electrical feedthrough is made of one or more biocompatible materials, and at least a portion of the electrical feedthrough is positioned beneath the aperture. The transceiver is configured to conduct RF communications. Further, the antenna element is electrically connected to the transceiver and is positioned below, above, or inside the electrical feedthrough.