Electrosurgical apparatus for generating radiofrequency energy and microwave energy for delivery into biological tissue

摘要

An isolating circuit 200 for an electrosurgical generator arranged to produce radiofrequency (RF) energy and microwave energy for treating biological tissue. The generator has an RF channel from an RF signal generator 218 and a microwave channel from a microwave signal generator 220 which are combined at a signal combining circuit 206 to enable the RF energy and microwave energy to be delivered into tissue along a common feed path. The isolating circuit comprises a tunable waveguide isolator 202 at a junction between the microwave channel and signal combiner, and can include a capacitive structure between a ground conductor of the signal combiner and a conductive input section of the waveguide isolator to inhibit coupling of the RF energy and leakage of the microwave energy. The isolating circuit can combine into a single tunable unit all the necessary components to isolate the microwave and RF channels from one another whilst providing a high withstanding voltage.