#$%^&*AU2010206119B220140410.pdf#####DIRECTIVE WINDOW ABLATION ANTENNA WITH DIELECTRIC LOADING Abstract An electrosurgical device for directing energy to a target volume of tissue s includes a coaxial feedline (226) having an inner conductor (220), an outer conductor (224) coaxially disposed around the inner conductor (220), and a dielectric material (222) disposed therebetween. An elongated electrically-conductive member (270) is longitudinally disposed at a distal end of the inner conductor (220). A balun structure (13) is disposed on the outer conductor (224). The device also includes an electricallyio conductive cylinder (540) coaxially disposed around a distal portion of the balun structure, and a dielectric structure disposed substantially adjacent to a distal end of the electrically-conductive cylinder (540), wherein the dielectric structure longitudinally extends from the distal end of the electrically-conductive cylinder (540) to a distal end of the electrically-conductive member (270).
