Electromagnetic-thermal Simulation Of Coaxial-fed Microstrip Antenna And Human Brain Based On Finite Element Method

With the rapid development of computer technology,finite element numerical analysis methods have become important tools for electromagnetic calculations,radio frequency antennas,and biological thermal effects analysis.This article will start from the finite element analysis method,not only to analyze the electromagnetic radiation characteristics of the microstrip patch antenna,but also to analyze the biothermal effect of the antenna on the human brain.Through the coupling of Maxwell's equations and heat transfer equations,the electromagnetic heat multi-physics coupling simulation of the interaction between the antenna and the human brain is realized.First,when using the finite element method to analyze the electromagnetic radiation characteristics of the antenna and the thermal distribution characteristics of the human brain,the first step is to give the object's electric field or temperature representation form based on the finite element method;the second step is based on the triangular or tetrahedral mesh Divide the object model and write the functional expression according to Maxwell's equations;the third step is to select the appropriate boundary conditions,construct the coefficient matrix and the right end vector,and finally obtain the approximate solution of the electric field or temperature.Then,the radiation characteristics of the coaxially fed microstrip patch antenna are studied,and the microstrip patch antenna array with large-scale periodicity is analyzed.According to the variational formula,based on the finite element analysis method,the coaxial-fed microstrip patch antenna is divided into a finite number of small tetrahedral grid cells,and an appropriate vector basis function is selected to represent the electric field,which converts the problem into a matrix equation solution,Solve the electric field value,you can get the radiation characteristics.Finally,in biothermology,the electric field distribution is obtained through Maxwell's equations,the specific absorption rate is calculated,and the specific absorption rate is used as the heat source to couple with the heat transfer equation;based on the time-domain finite element analysis method,convection boundary conditions and nonlinearity are introduced Radiation boundary conditions,and use the Crank-Nicholson difference scheme and fixed-point iteration method to solve the timedomain finite element system,and finally obtain the transient temperature change curve and steadystate temperature distribution.