#$%^&*AU2008212053B220130221.pdf#####FREQUENCY TUNING IN A MICROWAVE ELECTROSURGICAL SYSTEM ABSTRACT A method and apparatus is disclosed for the ablation of biological tissue to produce a therapeutic effect. An adjustment (540) is made to the output frequency of an electrosurgical generator (420) during the ablation cycle to accommodate changes in the electrical properties of the apparatus (400) and the biological tissues that occur as energy is transferred to the tissue. The adjustment is made to better align the source impedance with that of the load. 173/4 300O 500 L C50Q Fee331 Zu r Zu~=500 Generator FIG. 3C FIG. 3D 400-- ,kCable 450 Frequency AmplifierCope Generator -4.--Cupe Antenna 460 420 430 Display 435 Microprocessor oard 470 FIG. 4
