HDGS bandstop filter design by FGA

A new fuzzy genetic algorithm (FGA) is developed to optimize Hilbert fractal defected ground structure (HDGS), designed bandstop filter. The genetic operators (crossover and mutation) are self-adaptively adjusted by fuzzy controller of the algorithm, so convergent character and global optimization are improved. Fitness function is constructed by the HDGS stopband and pass-band transmission characteristics S₂₁. S₂₁ is obtained by using PML- FDTD method. To 500M-3GHz band center frequency of 2.4GHz, 200MHz bandwidth, the band stop filter is designed to target. The simulation results show that this method than the traditional genetic algorithm, faster convergence rate, and bandstop filter designed HDGS with large stop-band insertion loss and return loss, flat pass-band characteristics.