Abstract: To treat and diagnose tissue, a radiating antenna system is positioned within the tissue to radiate electromagnetic energy into a portion of the tissue desired to be heated, and a plurality of antenna elements are positioned for receiving and/or reflecting the radiated electromagnetic energy from the radiating antenna system. In certain applications, one or more of the antennas has an interior volume for receiving a heat exchange fluid to change the temperature of the tissue proximal to the receiving element.

Abstract: Medical systems and instruments which utilize microwave energy to provide heat treatment and diagnostic imaging of tissue are provided. One medical instrument has a collinear array having antennas configured to transmit electromagnetic energy so that the transmitted energy, in aggregate, is directed toward a desired area of the tissue. Another microwave medical system includes a catheter having an inflatable balloon in fluid communication with an inflation source, and an antenna having a radiating element positioned within the inflatable balloon to transmit electromagnetic energy toward the desired area of tissue. Still another medical instrument includes an antenna having receiving elements for receiving electromagnetic energy radiated from an electromagnetic source, rectifying devices, each having a first end electrically connected to a corresponding one of the receiving elements; and a transmission line electrically connected to a second end of each of the rectifying devices.