Tissue measurement and ablation antenna

A tissue treatment apparatus for delivering microwave frequency energy to biological tissue, the apparatus including:

• a microwave power source;
• a surgical antenna comprising:
• an elongated body with an inner conductor along a length thereof,
• an outer conductor surrounding the inner conductor and separated therefrom by a dielectric material,
• a connector connecting the inner conductor and the outer conductor to the microwave power source to receive microwave frequency energy from the microwave power source, and
• an insertion tip at a distal end of the elongated body, the insertion tip comprising an independent piece of dielectric material having an impedance at the microwave frequency that is different from an impedance at the proximal end of the antenna, wherein the insertion tip is configured to both act as a first impedance transformer to match the dielectric material of the elongated body with the tissue at the microwave frequency to radiate microwave energy from the distal insertion tip and to penetrate into the biological tissue;
• and
• a tuning filter arranged to dynamically match an impedance of the source to an impedance of a tissue load at the distal insertion tip,
• wherein the elongated body of the surgical antenna includes a second impedance transformer arranged to introduce a capacitive or inductive reactance into the surgical antenna.