Paper
In surface acoustic wave (SAW) filter, excessive temperatures can lead to degradation of performance or even damage to the device. Therefore, it is important to obtain temperature at the beginning of the design. In this paper, an automated electro-thermal model of SAW filter was established using MATLAB. The initial conditions required for the model are given, and after running the script, the thermal resistance matrix is automatically extracted, the circuit information is automatically extracted and the circuit is solved, and then the thermo-electric coupling is performed to find the steady-state value and save the result. Using this model, the temperature-frequency dependence and temperature distribution of the Band26 duplexer Tx path filter at 31.2 dBm input power are simulated. In addition, the temperature of the multilayer substrate filter under different substrate thicknesses and different $Q$ values is simulated.