Combined frequency microwave ablation system und devices

A system for delivering electrosurgical energy, the system including a housing having an antenna attached to the distal end thereof configured to receive a microwave signal and radiate energy at two or more wavelengths and a microwave generator operably connecting to the antenna that provides the microwave signal to the antenna. The microwave generator generates a combined microwave signal containing microwave energy having at least a first and a second wavelength; wherein the at least a first and second wavelengths are capable of creating resonance in the antenna.