A new FDTD model of microwave susceptors on curved surfaces

Susceptors are thin lossy metal layers used to control local dissipation of power during microwave heating processes. While they may have a dominant effect on final temperature patterns, their electromagnetic modeling has been a long recognized challenge, due to small transverse dimensions, microwave semi-transparency, and complicated shapes. This work addresses effective representation of susceptors deposited upon or buried within microwaveable food packages of non-Cartesian geometries. It focuses on packages shaped as cylinders or truncated cones, which are non-trivial to be described on a Cartesian mesh, but more easy to define in a cylindrical system. Borrowing from previous experience with soft and hard antenna surfaces, an idea of simplifying the susceptor structure is proposed. Two specific models are implemented in the FDTD environment and validated. Computational examples prove a significant reduction in RAM and CPU requirements, within a permissible accuracy margin. Conclusions apply to potential use of the new models for microwave heating simulations, but also emphasis synergy effects between various microwave technologies.