Resonant power absorption is an important phenomenon during microwave heating. The
resonances that occur when plane electromagnetic waves are incident on infinitely long
cylinders and slabs are investigated as a function of sample dimensions. For cylinders two
kinds of incident waves are studied: TMz when the electric field is oriented along the axis of
the cylinder and TEz when the magnetic field is oriented along the axis. At a resonant
condition the overage power absorbed by the sample is a local maximum. Due to …

Resonant microwave power absorption is examined for slabs exposed to TEM waves from
both faces and for a slab placed on a reflecting support. Using the electric field distribution in
the slab, the average power is obtained by integrating the spatially distributed power across
the sample length. Due to constructive interference of the standing waves within the sample,
the average power rises to a local maximum during a resonance. Irrespective of the material,
resonances occur at integral values of L/λs when the slab is exposed to radiation from both …