The FDTD Computing Of Electromagnetic And Thermal About Microwave Circuit

With the development of microwave circuit miniaturization and large scale intergrated,the joule heat generated by circuit loss is accumulating. When the input signal is high powerelectromagnetic pulse, the accumulation of heat more quickly, the electrical parameters of thecircuit changes, affect the normal work of the circuit components, reduce the reliability of thecircuit, and even may lead to deformation, breakdown, and burned of the circuit. So asmicrowave circuit is widely used in the field of wireless communication, radio frequencyidentification and global positioning system, the electromagnetic field and thermal field of thephysical field in microwave circuit has become the research hot spot.In this paper, using the method of finite difference time domain (FDTD) to establishmicrowave circuit model with lumped components to achieve electromagnetic analysis ofmicrowave circuit with lumped components, and using finite difference method (FDM) toestablish heat conduction equation of lumped components to achieve heat transferperformance analysis of lumped components. Based on the algorithm model, this paperprobes into the factors that affect single heat transfer of microwave circuit, numericalexperiments show that thermal diffusion coefficient, power loss, pulse number per unit timeare the main factors influencing heat accumulation of microwave circuit. Among them, thethermal diffusion coefficient associated with cooling conditions, the smaller of the thermaldiffusion coefficient, the worse of the heat dissipation performance of surround environmentor heat sink; Power loss associated with the power of the input signal, the greater of the signalpower, the more of the joule heat; Pulse number per unit time is closely related to the carrierfreguency, the bigger of the carrier frequency, the more quickly of the accumulation of heat.To establish electromagnetic heat integration FDTD computing model about microwavecircuit with lumped components, is conducive to further research of active microwave circuitand electromagnetic heat distribution characteristics of complex microwave circuit foreffective heat dissipation and electromagnetic protection.