The use of single-mode cavities has been recognized as a viable technique for sintering and joining ceramics and for creating microwave plasma for materials processing. It is often reported, however, that tuning these cavities at lower and higher temperatures critically depends on the types of materials being processed, the variation of ε* as a function of temperature, the size and shape of samples, and the overall heating system configuration with and without insulation.

In this paper we use the finite-difference time-domain technique to address the performance of the single-mode cavity heating system under a wide variety of heating conditions and system configurations. Specifically, practical issues such as limiting values of sample sizes, the dependence of optimal sample sizes on the complex permittivity of materials under test, the role of sample shape on enhancing uniformity of heating patterns, and various tradeoffs involved in utilizing various cavity modes and/or SiC rods as stimulus for heating large samples are evaluated.