An implantable device (10), respectively an implantable medical device (10), is provided that comprises data communication means which include means (21) for altering an oscillatory electric field imposed on body tissue surrounding the implantable device (10). In a first embodiment, the means (21) for altering an oscillatory electric field are configured to modulate an impedance of a conductive medium surrounding the implantable device (10) when the implantable device (10) is within an oscillatory electric field. In an alternative embodiment, the means (29) for altering an oscillatory electric field comprise means (29) for generating an oscillatory electric field that is phase-synchronized with an oscillatory electric field imposed on a conductive medium surrounding the implantable device (10).
