Simulation and experiment of microstrip lines temperature rise based on COMSOL Multiphysics

Conductor loss and dielectric loss of the microstrip line can lead to temperature rise and limit the power capacity of the microstrip circuit. This involves the interaction (coupling) between the electric and temperature fields. In this study, the factors affecting the temperature rise of the microstrip line were analyzed by means of the parallel plate model. In addition, based on COMSOL Multiphysics simulation software, the influence of dielectric dissipation factor tanδ of microstrip lines of FR4 and RO4350B on the temperature rise per unit input power (TRPIP) was simulated. The simulation results under the set basic parameters show that the TRPIP of the strip conductors of the FR4-substrate microstrip lines with tanδ of 0.02 is about 4.8 °C, and that of RO450B-substrate microstrip lines with tanδ of 0.0037 is about 1.38 °C. Finally, in order to verify the simulation results, a non-invasive measuring device with an infrared camera was constructed to measure the heat distribution on the surface of the microstrip line.