A microwave antenna assembly includes first and second elongated conductors, and a dielectric body portion. The first elongated conductor is associated with a first radiating portion at least partially along the length thereof. A second elongated conductor is disposed within the first elongated conductor and is associated with a second radiating portion at least partially along the length thereof. The dielectric body portion is disposed along the length of at least one of the first and second elongated conductors and the dielectric body portion includes two or more radial partition of dielectric material having difference dielectric constants.
