Electromagnetic-thermal coupling computation of the high power microwave feed output window

This work develops a hybrid finite-difference time-domain (FDTD) method to calculate the electromagnetic field and temperature distribution of the high power microwave feed output window. First, the electromagnetic field of the microwave feed is computed, by which the electromagnetic heating source of the output window can be obtained. Then the partial differential equation of heat conduction is solved numerically. The influence of the temperature on electromagnetic parameters is considered in the model. The calculation is performed in the two-dimensional (2-D) cylindrical coordinate system, in which conformal FDTD techniques are used to handle the oblique PEC wall of the feed and cylindrical CPML is used to truncate the computational domain. The model is validated by the calculation results. The proposed method can be used in the analysis of unsteady temperature field of the output window.