#$%^&*AU2015215971B220161103.pdf#####MICROWAVE ANTENNA ASSEMBLY HAVING A DIELECTRIC BODY PORTION WITH RADIAL PARTITIONS OF DIELECTRIC MATERIAL Abstract An electrosurgical system (100) for treating tissue, the system (100) comprising an electrosurgical generator (102) configured to generate microwave energy and an antenna assembly (300) configured to radiate the microwave energy. The antenna assembly (300) comprising a first elongated conductor (302) associated with a first radiating portion (306) at least partially along the length thereof and a second elongated conductor (304) disposed within the first elongated conductor (302) and associated with a second radiating portion (308) at least partially along the length thereof The antenna assembly (300) further comprises a dielectric body portion (318) disposed along the length of at least one of the first elongated conductor (302) and the second elongated conductor (304). The dielectric body portion (318) including at least two radial partitions of dielectric material having different dielectric constants. The electrosurgical generator (102) includes an S-parameter sensor (234) configured to determine at least one S-parameter of the antenna assembly (300) and wherein the first dielectric body portion causes the first radiating portion (306) to have a radiation pattern including at least one elongated radiation lobe (338), wherein the electrosurgical generator (102) associates the determined at least one S-parameter with an angular direction of the at least one elongated radiation lobe (338).
