A medical implant comprising a housing and an antenna member carried by the housing. The antenna member is configured to be capacitively coupled to body tissue in which the housing is implanted. This forms, together with the impedance of the body tissue, part of a resonant circuit. A reference electrode carried by the housing as a return for the antenna member also forms a further part of the resonant circuit. Transceiver circuitry is also provided and is operable as at least one of a source and a load for the antenna member and forms yet a further part of the series resonant circuit.
