Modeling of Nonuniform Coupled Transmission Lines Interconnect Using Genetic Algorithms

Ahmad CHELDAVI  Gholamali REZAI-RAD  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E83-A   No.10   pp.2023-2034
Publication Date: 2000/10/25
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: PAPER
Category: Communication Theory and Signals
modeling,  characterization,  nonuniform transmission lines,  genetic algorithms,  

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Based on genetic algorithm (GA) in this paper we present a simple method to extract distributed circuit parameters of a multiple coupled nonuniform microstrip transmission lines from it's measured or computed S-parameters. The lines may be lossless or lossy, with frequency dependent parameters. First a sufficient amount of information about the system is measured or computed over an specified frequency range. Then this information is used as an input for a GA to determine the inductance and capacitance matrices of the system. The theory used for fitness evaluation is based on the steplines approximation of the nonuniform transmission lines and quasi-TEM assumptions. Using steplines approximation the system of coupled nonuniform transmission lines is subdivided into arbitrary large number of coupled uniform lines (steplines) with different characteristics. Then using modal decomposition method the system of coupled partial differential equations for each step is decomposed to a number of uncoupled ordinary wave equations which are then solved in frequency-domain.