Computational Characterization of a Composite Ceramic Block for a Millimeter Wave Heat Exchanger

Electromagnetic and electromagnetic-thermal coupled problems are solved by the finite-difference time-domain technique for an AlN:Mo composite ceramic block backed by a thin metal plate and irradiated by a high-power W-band plane wave. Computation is based on experimental data on temperature-dependent complex permittivity, specific heat, and thermal conductivity. Non-uniformity of patterns of dissipated power and temperature is quantified via standard-deviation-based metrics. A 10×10×10±2 mm block of the composite with concentration of Mo from 0.25 to 4% is considered as irradiated by the plane wave with power density on the block’s front surface from 0.3 to 1.0 W/mm2 at 95 GHz. It is shown that the block can be heated up to 1000 oC highly uniformly for 50–110 s. The composite producing maximum total dissipated power is found to have Mo content about 3%.