Optimum design of microwave absorbing materials based on modified genetic algorithms

In order to solve the problems of the slow convergent speed and non-global convergence of the canonical genetic algorithm called the simple genetic algorithm in the optimal procedure for broadband microwave absorbing materials with high absorptivity, a new modified genetic algorithm is presented. With the novel selection strategy, convergence and proceeding operators can enhance global searching ability and quicken convergent speed of the canonical genetic algorithm. The new algorithm can adaptively adjust the probabilities of crossover and mutation. Optimum design software of microwave absorbing materials based on modified genetic algorithm can adaptively adjust its parameters and it is programmed using Visual C⁺⁺ language. The algorithm is proved to be global convergence by an enumeration method. Structure optimization of microwave absorbing materials is performed based on existing database of electromagnetic parameters for microwave absorbing materials. Result indicates that the absorber with two layers (inner layer thickness is 0.9 mm, outer layer thickness is 2.7 mm and total thickness is 3.6 mm) can be obtained. Its reflectivity is lower than -15 dB at 8-18 GHz.