An embodiment of a dual port antenna system includes a balanced 90.degree. hybrid coupler integrated with a crossed-field antenna to provide stable high isolation between the two input ports of the system. Unlike conventional antennas, the crossed-field antenna is made up of two radiating elements separately fed at a phase difference of 90.degree.. This allows all of the power from the two transmitters to be coupled to the antenna via the hybrid coupler. A balanced 90.degree. hybrid coupler provides isolation between the two ports of the system by matching the electrical characteristics of the antenna. The isolation between ports provided by the balanced 90.degree. hybrid coupler is approximately 35-40 db which is sufficient to allow the independent operation of transceivers connected to the input ports. The crossed-field antenna exhibits loose electrical coupling so that the electrical characteristics remain stable and sufficiently high isolation between input ports is maintained.