Abstract: A packaging system is disclosed which includes a susceptor that heats when exposed to microwave radiation, and which has a selective responsiveness to microwave radiation. The susceptor surface has a plurality of regions, where at least one region has an altered responsiveness to microwave radiation which is achieved by disruptions in the susceptor surface. A method for making regions of a susceptor selectively responsive to microwave heating by disrupting the continuity of the metallized film of the susceptor is also disclosed.

Abstract: An apparatus for heating a food item in a microwave oven is disclosed which has heater regions in combination with a reflective lattice structure. The combination of the reflective lattice structure and heater regions provides a food heating device which substantially maintains its reflectance, absorbance and transmittance during microwave heating. Substantial uniformity of heating is also achieved. The reflectance, transmittance and absorbance of the food heating device can be adjusted by changing the relative configuration and construction of the lattice structure and the heater regions.

Abstract: A method and apparatus is disclosed for a system for heating food products in a variety of microwave ovens. The invention allows the temperature profile of the food product to be set at a predetermined level. A grid is used in combination with a conductive ring. There is preferably a spacing between the grid and the surface of the food product between about 0.25 inch and about 2.4 inches, a margin between openings in the grid between about 0.6 inch and about 1.8 inches, and the openings in the grid are of a size between about 0.75 inch and about 1.75 inches. A single iris embodiment is disclosed. The single iris may be in contact with the surface of the food product or spaced therefrom. An embodiment is also disclosed wherein a grid is in contact with the food surface.

Abstract: A food package for a microwave oven is disclosed which has a grid in combination with a susceptor means. The combination of the grid and susceptor means provides a heater element which substantially maintains its reflectance, absorbance and transmittance during microwave heating. Substantial uniformity of heating is also achieved. The reflectance, transmittance and absorbance can be adjusted by changing certain design factors, including hole size, susceptor impedance, grid geometry, spacing between the grid and susceptor, and the spacing between adjacent holes.

Abstract: A method and apparatus for measuring strong microwave electric field strengths is disclosed. The apparatus includes a first active temperature probe in cooperation with susceptor means for measuring a temperature indicative of the heating effects of microwave radiation at a test location, and an ambient temperature probe for measuring ambient temperature. The temperature differential between the two probes is used by calibration means for determining electric field strength at the test location. The method includes the steps of heating a susceptor means with microwave radiation, and measuring a temperature indicative of the heating effects of microwave radiation at the test location. Ambient temperature is measured, and the temperature differential used to determine the magnitude of the electric field strength.