Abstract: A dipole microwave applicator emits microwave radiation into tissue to be treated. The applicator is formed from a thin coax cable having an inner conductor surrounded by an insulator, which is surrounded by an outer conductor. A portion of the inner conductor extends beyond the insulator and the outer conductor. A ferrule at the end of the outer conductor has a step and a sleeve that surrounds a portion of the extended inner conductor. A tuning washer is attached to the end of the extended inner conductor. A dielectric tip encloses the tuning washer, the extended inner conductor, and the sleeve of the ferrule. The sleeve of the ferrule and the extended inner conductor operate as the two arms of the dipole microwave antenna. The tuning washer faces the step in the ferrule, and is sized and shaped to cooperate with the step in balancing and tuning the applicator.

Abstract: Radiation applicators comprise an elongate device having an antenna (240, 340) at their tip for coupling radiation into biological tissue and a dielectric body (250, 350) surrounding the antenna so as to encompass substantially the whole of the near-field region of the antenna and/or to enhance transmission of radiation in the forward direction. The body (250, 350) may be cylindrical with the antenna (240, 340) along its axis. The antenna may be ?/2 in length and ?/2 in radius. The tip (270) of the antenna (240) may be rounded hemispherical with radius ?/2 to enhance forward transmission of radiation. The dielectric constant (?) of the body (250, 350) is as high as possible to reduce its diameter at a desired operating frequency but may be matched to the surrounding tissue by another layer of dielectric material (380) with a value (?) intermediate that of the core (360) of the body (350) and the tissue.

Abstract: A probe (1) is designed to propagate and radiate microwave electromagnetic energy in a controlled fashion. The probe (1) includes at least one waveguide (2) of cross-section which would not normally pass microwaves at the operational frequency. The waveguide (2) therefore includes dielectric material (5), such as alumina, in the form of a rod an exposed portion of which forms an antenna. The probe is preferably for use in endometrial ablation and therefore the reduced dimension of the waveguide can be made compatible with the narrow neck of the uterus.