Disclosed technology is related to RF generators and feedback control system is used to adjust the electrosurgical unit that the electrical power is transmitted to cutting long filament (that is, cutting electrode). The energy of electrosurgical unit uses, to form cutting arc shape work piece in ablation tissue block access target tissue. The instrument forms basket container surroundings target tissue to receiving consumption tax target tissue from ablation tissue block. When instrument forms the length of container, the variation of exposed filament ablation tissue. Therefore, during RF power generation mechanisms described herein cause to change the expansion of the general power transmitted, in differential phase angle of the measured value between of instrument base output power, current sense output and voltage sensing output, in some embodiments, to keep uniform power density along length exposed filament.
