Radio frequency isolation card

An antenna system (5) comprising: a plurality of antenna elements (10) a supply network (15, 17) coupled to each of the antenna elements, for communicating the electromagnetic signals from and to each of the antenna elements (10); and a feedback system (45) coupled relative to the supply network (15, 17) and the antenna elements (10) for generating a feedback signal to at least one of the antenna elements comprising the feedback system ( 45) one disposed on one side of a planar dielectric support flat conductor (55) strip having flat conductive strip (55) having a length, width, and thickness wherein the length and width are larger than the thickness, generating conductive strip feedback signal in response to reception of electromagnetic signals by the antenna elements (10) transmitted, operating the feedback signal to cancel a leakage signal present at the desuministro network (15, 17) and thereby enhancing way port to port isolation of the antenna system (5); wherein the feedback system comprises at least one further planar conductive strip (55) disposed on one side of the flat dielectric support.