An electrosurgical instrument includes an elongated housing having proximal and distal ends. The proximal end is configured to couple to a source of electrosurgical energy via first and second channels extending along a length of the housing to the distal end thereof. The distal end includes a reflector having a dielectric load operably coupled thereto and configured to receive at least a portion of the first conductor therein. In a first mode of operation, electrosurgical energy is transmitted to the first channel and reflected from the reflector to electrosurgically treat tissue. The reflector is configured to receive at least a portion of the second channel therein. In a second mode of operation, electrosurgical energy is transmitted to the second channel to dissect tissue.