A microwave heating system configured to heat a plurality of articles is provided. The microwave heating system can include one or more microwave launchers that define at least one launch opening having a depth of not more than about 0.625λ, wherein λ is the predominant wavelength of the microwave energy passing through the launcher. Additionally, in some embodiments, the launch opening may have a width or depth that is less than the corresponding inlet dimension, such that the microwave launcher has a generally tapered profile. When the microwave launcher includes a single inlet and two or more launch openings, the center points of adjacent outlets may be laterally spaced from one another relative to the direction in which the articles are passed through the heating chamber.
