Electrosurgical instrument with dual radiofrequency and microwave electromagnetic energy

An electrosurgical resection instrument for applying to biological tissue radiofrequency (RF) electromagnetic (EM) energy having a first frequency and microwave EM energy having a second frequency higher than the first frequency, the electrosurgical resection instrument comprising:

• an instrument tip comprising a planar transmission line element, the planar transmission line element comprises a substantially planar element made from a first dielectric material, a first conductive layer on a first surface of the substantially planar element, and a second conductive layer on a second surface of the substantially planar element, the first surface and the second surface forming respectively a top side and an underside of the instrument tip;
• a coaxial cable comprising an inner conductor, an outer conductor coaxial with the inner conductor, and a second dielectric material separating the outer conductor and the inner conductor, the coaxial cable being for conveying, simultaneously or separately, an RF signal having the first frequency and a microwave signal having the second frequency;
• a carrier tube defining a lumen for carrying the coaxial cable, wherein the instrument tip comprises a distal portion that protrudes beyond a distal end of the carrier tube;
• and
• a third dielectric material mounted on the distal portion of the instrument tip to cover the second conductive layer on the underside of the distal portion of the instrument tip, the third dielectric material having an outer surface that curves upwards along its length towards a distal end of the instrument tip;
• wherein the first surface of the substantially planar element and the second surface of the substantially planar element extend towards the distal end of the instrument tip between the first conductive layer and the second conductive layer in a direction parallel to a longitudinal axis of the coaxial cable;
• wherein the inner conductor is electrically connected to the first conductive layer and the outer conductor is electrically connected to the second conductive layer to enable the instrument tip to receive the RF signal and the microwave signal.