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

An electrosurgical apparatus for resection of a biological tissue, the apparatus comprising:

• a radiofrequency (RF) signal generator for generating RF electromagnet (EM) radiation having a first frequency;
• a microwave signal generator for generating microwave EM radiation having a second frequency that is higher than the first frequency;
• a probe arranged to deliver the RF EM radiation and the microwave EM radiation separately or simultaneously from a distal end thereof;
• and
• a feed structure for conveying the RF EM radiation and the microwave EM radiation to the probe, the feed structure comprising an RF channel for connecting the probe to the RF signal generator, and a microwave channel for connecting the probe to the microwave signal generator,
• wherein the RF channel and microwave channel comprise physically separate signal pathways from the RF signal generator and microwave signal generator respectively,
• wherein the feed structure includes a combining circuit having a first input connected to the separate signal pathway on the RF channel, a second input connected to the separate signal pathway on the microwave channel, and an output connected to a common signal pathway for conveying the RF EM radiation and the microwave EM radiation separately or simultaneously along a single channel to the probe,
• wherein the microwave channel includes a waveguide isolator connected to isolate the separate signal pathway on the microwave channel from the RF EM radiation,
• wherein the waveguide isolator has an adjustable impedance,
• wherein the combining circuit is integrated with the waveguide isolator,
• wherein the output connected to the common signal pathway includes an output probe mounted on the output section of the waveguide isolator, the output probe having a coupling conductor extending into the waveguide isolator to couple the microwave EM energy therefrom, and
• wherein the first input includes an RF connector mounted on the waveguide isolator, the RF connector having a signal conductor that extends into a waveguide cavity of the waveguide isolator to electrically contact the coupling conductor of the output probe.