Auto Designing Of Dual-Band Bandpass Filter Based On Improved Genetic Algorithm

Dual-Band Bandpass Filter can be used in two different frequency bands simultaneously, it can minimize the dual-band communication system and improve the stability and reliability of the dual-band communication system. So Dual-Band Bandpass Filter plays a significant role in realizing dual-band communication and a rather broad market is behind.This paper proposes a Dual-Band Bandpass Filter auto design method based on a Variant of Canonical Genetic Algorithm. Using improved algorithm to optimize structure or components values of the Dual-Band Bandpass Filter without knowing them in advance globally, according to the performance target of the filter. Consequently the structure and component parameter’s automatically configuration can be realized. This method can solve the problems that classical design method can’t deal with, such as high human disturbance factors and calculation complication. It can be implemented easily automatically without knowing the structure or or component parameter values. The main researches of this paper are as follows,1. Variant of Canonical Genetic Algorithm is proposed based on the study of Canonical Genetic Algorithm. Three main changes are as follows, adopting the classification to population, change of selection strategy and improvement of crossover and mutation strategy.2. Design Single Band Filter using the Variant of Canonical Genetic Algorithm, and compared with classical method and Canonical Genetic Algorithm, to verify the effectiveness and possible problems in the process of design.3. Design the Dual-Band Bandpass Filter using the Variant of Canonical Genetic Algorithm, of which the two frequency bands can given randomly. Structure and component parameter values are optimized simultaneously, hence structure and component parameter’auto design is realized.4. Design the widely used Dual-Band Bandpass Filter of2.4/5.2GHz in wireless communication, using the improved algorithm and the method in the existing literature. Comparison of the two results shows that the method in this paper gets the better result. The experiment of circuit component parameter value’s sensitivity is made in this paper to observe difference of filter’s Dual-Band performance. The parameter values of the components in this experiment are changed about by5%.5. Try to design Tri-Band Bandpass Filter using the method in this paper. Design success and get the simulation result. Deficiency is also found in the process of designing that the balance between filter circuit size and good filter performance is difficult to keep.To sum up, the design method proposed in this paper has high level of automation, and the designed Dual-Band Bandpass Filter’s performance is better than the designed result using other method mentioned in this paper. What is more significant that the method proposed in this paper can be used to design any Dual-Band Bandpass Filter with any two frequency bands.