Calculation of the electrical parameters of planar transmission lines for computer-aided microwave filter designs with the aid of fuzzy logic

Parallel to the rapid development of communication systems, the need for high-performance, low-cost miniature circuit design and production has also increased. For this reason, the searches for planar transmission lines in different configurations with desired properties have gained momentum. In line with these searches, it is of great importance to analyze the planar transmission lines with high speed and accuracy. At this point, microwave researchers resort to appropriate CAD (Computer Aided Design) programs to perform these analyses. In this thesis, a visual CAD software program has been designed to meet the high speed and accuracy calculation and modeling needs, which are very important for researchers in the analysis, synthesis, modeling and design processes of microwave filters. As components of the program, sub-design tools that can work dependently/independently have been developed. Quasi-static analysis and frequency-dependent full-wave analysis approaches, which offer frequency-independent solutions, are used in the theoretical analysis of planar transmission lines. In this thesis, CMT (Conformal Mapping Technique), a quasi-static analysis technique, is used to calculate the electrical parameters of planar transmission lines. Techniques that can offer alternative approximate solutions independent of theoretical solutions are needed for reasons such as the difficulty of planar transformation processes and the complexity of equation solutions in the analysis made with CMT. In complex applications, a system is expected to best represent the input/output parameter relationships and achieve optimal modeling. For this purpose, fuzzy systems are used to model the system for a more practical solution. Thus, fuzzy logic system approaches can offer an alternative solution independent of theoretical approaches. Within the scope of this thesis, a solution based on the SFC (Subtractive Fuzzy Clustering) technique, which can be an alternative to the theoretical solutions used in microwave problems, is presented.