Abstract: A microwave applicator for applying microwave energy to living tissue for providing uniform heating without hot spots. The applicator includes a first electrical conductor and a second electrical conductor substantially shielding the first conductor in a transmission line configuration capable of propagating microwave energy in a frequency band suitable for heating living tissue. The first conductor has an unshielded portion extending a distance beyond the second conductor and there is additionally provided a coil as a third electrical conductor surrounding the extending portion of the first conductor and connected between the ends of the first and second conductors. The applicator is preferably configured for insertion through an opening into the body and includes a substantially smooth dielectric sleeve covering the coil of the third conductor.

Abstract: An antenna system for producing from a fixed array of active antenna elements which are each omnidirectional in a plane, a sensitivity pattern that is directional in said plane and which pattern can be rotated around the array. The system consists of at least three antenna elements located at the corners of a regular polygon and are excited with substantially equal magnitudes of current that are in the same phase at two adjacent corners and different in phase by substantially 90 electrical degrees at the third corner. The antenna system further includes an electrical power dividing and phasing network as well as electrical switching means to effect proper rotation.

Abstract: A feather-edge conductive pattern is sandwiched between two ferrite bars so s to cause different degrees of residual magnetism in the bars. Two other blocks of materials having relative high dielectric constants sandwich the ends of the bars, and the whole device is inclosed in a waveguide which will have variable phase shifts in accordance to the residual magnetism of the bars.