Radio frequency isolation card

One or more feedback elements generate a feedback signal in response to a transmitted signal outputted by each radiator of the antenna system. This feedback signal is received by each radiator, also described as a radiating element, and combined with any leakage signal present at the port of the antenna. Because the feedback signal and the leakage signal are set to the same frequency and are approximately 180 degrees out of phase, this signal summing operation serves to cancel both signals at the output port, thereby improving the port-to-port isolation characteristic of the antenna. Each feedback element can include a photo-etched planar metal strip supported by a planar dielectric card made from printed circuit board material. Such feedback elements can provide a high degree of repeatability and reliability in that the manufacturing of such feedback elements can be precisely controlled.