Abstract: A microwave applicator comprising a coaxial electrical input (4) and a waveguide (1) filled with dielectric (2), an inner conductor (7) of the coaxial input extending longitudinally within one end of the waveguide to launch microwaves in the TM01 mode to travel to the distal end face (8) of the waveguide so that microwaves are transmitted when the distal end face is contacted by the biological tissue to be treated.

Abstract: A microwave applicator for applying electromagnetic radiation at microwave frequency includes a coaxial input for a microwave signal input and a waveguide for receiving and propagating the microwave signal input. Dielectric material is positioned within the waveguide and extends beyond the waveguide to form an antenna for radiating microwave energy. The coaxial input has direct in-line transition to the dielectric-filled waveguide. Preferably, this direct in-line transition is achieved by the central conductor of the coaxial input extending axially centrally into the waveguide so as to excite microwaves in the waveguide. A lateral conductor extends radially from the central conductor to assist the launch of the microwaves into the waveguide. Preferably, the applicator includes a temperature sensor which is directly connected to the coaxial input.

Abstract: A method of positioning on a microwave waveguide a sensor (20) including an elongate metallic element (23, 24) comprising: selecting a tubular waveguide (12); determining the general orientation of the magnetic field (3) generated during microwave transmission; and positioning the elongate metallic element (20, 23, 24) substantially parallel to the orientation of the magnetic field (3). Connections (23, 24) of the sensor (20) extend longitudinally of the waveguide (12) and are connected to the outer wall (25) of the waveguide and the central conductor (16) of the coaxial cable (15) that powers the waveguide.

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.