The term “a substantial number of magnetic field lines” passing through the implantable receiver coil refers to an electromagnetic coupling between the transmitter coil and the implantable efficiency such that a coupling coefficient between the external coil and the implantable receiver coil is at least 0.5, preferably 0.6, more preferably 0.7, even more preferably 0.8 and the most preferably 0.9. It is apparent that in embodiments utilizing closed loop structure, leakage of field lines/magnetic flux is minimized and a significantly higher coupling coefficient of at least 0.7, preferably 0.8 and even more preferably 0.9 is achieved. In embodiments utilizing the open loop structure, the sandwiched skin and body tissue may result in some magnetic flux/field lines leakage, thus leading to a reduction in coupling coefficient when compared to the closed loop structure. Nonetheless, even in such embodiments, a coupling coefficient of at least 0.5, preferably at least 0.6 and more preferably 0.7 is achieved. Despite the coupling coefficient in the open loop structure embodiments being a function of thickness of the skin and body tissue, the coupling coefficient is still higher than the conventional wireless transcutaneous link comprising parallel transmitter coil-receiver coil set up because the open loop structure is adapted to guide the magnetic field lines generated in response to excitation of the transmitter coil in a focused way towards the implantable receiver coil. The term may also refer to “a substantial number of magnetic field lines” the magnetic field lines generated in response to the excitation of the transmitter coil being primarily concentrated within the loop structure and also passing through the implantable receiver coil. The substantial number of magnetic field lines may also be understood as a substantial amount of magnetic flux, which is generated in response to excitation of the transmitter coil.