EM-Based Microwave Filter Synthesis by Genetic Algorithms

• Main Authors: Liang, Fong-Lieh, 梁逢烈
• Other Authors: C. K. C. Tzuang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/50740252433365145093

碩士 === 國立交通大學 === 電信研究所 === 85 === Genetic algorithms (GA) have been widely applied to a lot of fields such as artificial intelligence, circuit synthesis and optimization as design tools and problem solvers because of theisr global versatility and ablity to optimize in complex multimodal search spaces. We adopt the concept of GA and program new filter design tools with the application of the 3-D full wave EM simulator as the simulation engine. To validate that GA could be used to solve the traditional optimization problems and the most characteristics it owns is superior than traditional methods, we design two different usgae of GA respectively: (1) For the optimization of continuous variables. We take the geometry parameters of the bandstop filter structure as the variables and the centerfrequency is shifted from 15 GHz to 13 GHz successfully under our specifications.This illustrates that the concept of GA could be implemented as the traditional optimizer to find the best design. (2) For the optimization of discrete variables. We take the existence of unit patches, which are gridded from the region needed to be optimized, as the optimization variables. We specify that the |S21| of the open stub is less than 0.3 at 6 GHz. From the intermediate results, we find a simple rule between the best design of the generation. We discover the phenomena corresponding to the results of physical explnation. Theconclusion is made to explain that state-of-the-art optimization application of GA could also be demonstrated as the evolution of real world creatures.