Optimization design of ground plane PBG structure of T-shape microstrip line by improved FGA

A new fuzzy genetic algorithm (FGA) is developed to reduce crosstalk of T-shape microstrip lines in high speed circuit systems, which is used to optimize the ground plane with photonic bandgap (PBG) structure. The genetic operators (crossover and mutation) are adjusted self-adaptively by fuzzy controller and good convergent character and global optimization are improved. Based on the PML-FDTD method, the fitness value is established by taking the sum of weighted performance index function of crosstalk and return loss, through which is optimized the crosstalk between T-shape microstrip line and adjacent line in the ground plane. Comparing the simulation results of the fitness function using different parameters, numerical results demonstrate that the crosstalk is decreased 8 dB which is caused by T-shape microstrip line and adjacent line above the photonic- bandgap ground. Then the return loss and the signal distortion reduce effectively.