A wireless receiver for use in a Transcutaneous Energy Transfer, TET, system, comprising: a hermetically sealed housing ; receiver electronics contained in the hermetically sealed housing; a low-frequency ferrite material surrounding the hermetically sealed housing, the low-frequency ferrite material configured to reduce the amount of magnetic flux that reaches the hermetically sealed housing; an antenna body coupled to the low-frequency ferrite material, wherein the antenna body has at least first and second symmetry lines perpendicular to each other and crossing substantially in the center of the antenna body; a plurality of conductive elements (508a-h) disposed on the antenna body in a pattern that is mirrored along the first and the second symmetry lines; at least one feed line located substantially in the center of the pattern formed by the plurality of conductive elements, the feed line comprising: a differential transmission line (822, 824 and 826) electrically connecting the plurality of conductive elements to the receiver electronics and configured to deliver RF energy to the plurality of conductive elements to transmit and receive radio information; the plurality of conductive elements comprising at least first and second conductive elements extending from the feed line in opposite directions with respect to the first symmetry line; and a plurality of gaps (510a-p) positioned between adjacent conductive elements, the gaps configured to prevent or reduce induction of current in the plurality of conductive elements when the antenna is exposed to a magnetic field. a hermetically sealed housing ; receiver electronics contained in the hermetically sealed housing; a low-frequency ferrite material surrounding the hermetically sealed housing, the low-frequency ferrite material configured to reduce the amount of magnetic flux that reaches the hermetically sealed housing; an antenna body coupled to the low-frequency ferrite material, wherein the antenna body has at least first and second symmetry lines perpendicular to each other and crossing substantially in the center of the antenna body; a plurality of conductive elements (508a-h) disposed on the antenna body in a pattern that is mirrored along the first and the second symmetry lines; at least one feed line located substantially in the center of the pattern formed by the plurality of conductive elements, the feed line comprising: a differential transmission line (822, 824 and 826) electrically connecting the plurality of conductive elements to the receiver electronics and configured to deliver RF energy to the plurality of conductive elements to transmit and receive radio information; the plurality of conductive elements comprising at least first and second conductive elements extending from the feed line in opposite directions with respect to the first symmetry line; and a plurality of gaps (510a-p) positioned between adjacent conductive elements, the gaps configured to prevent or reduce induction of current in the plurality of conductive elements when the antenna is exposed to a magnetic field. a differential transmission line (822, 824 and 826) electrically connecting the plurality of conductive elements to the receiver electronics and configured to deliver RF energy to the plurality of conductive elements to transmit and receive radio information; the plurality of conductive elements comprising at least first and second conductive elements extending from the feed line in opposite directions with respect to the first symmetry line; and a plurality of gaps (510a-p) positioned between adjacent conductive elements, the gaps configured to prevent or reduce induction of current in the plurality of conductive elements when the antenna is exposed to a magnetic field. <EOS>