In this thesis, the parameter extraction process of equivalent circuit models of a composite right/left-handed (CRLH) transmission line (TL) is studied. First, an introduction to metamaterial (MTM) structures, and a brief description of the two main approaches of modeling a CRLH TL, are described. Next, it is reviewed the basic theory of modeling a purely righthanded (PRH) transmission lines by means of using ABCD-parameters. After obtaining a conventional TL model, we analize our circuital responses and compare them with the expected behavior published in the literature. Next, it is reviewed the basic theory of modeling a purely left-handed (PLH) TL by means of using ABCD-parameters. After obtaining a model of PLH TL, we analize our circuital responses and compare them with exact theoretical results published in MTM literature. Next, it is also reviewed the basic theory of modeling a CRLH TL, comparing our responses again with exact theoretical results. Next, based on previous learning of PRH TL, a parameter extraction (PE) strategy is employed on an actual microstrip structure simulated in Sonnet. Applying a minimax formulation using the Nelder-Mead method, the equivalent RGLC average values are extracted using Matlab. Later, a compilation of several CRLH TL structures are described, including its S-parameter responses. Two main groups of them are described: those using microstrip technology only, and those using surface mount technology (SMT) devices soldered over microstrip technology. Next, one of the structures is selected to finally implement a PE strategy, extracting its equivalent RGLC average values of the CRLH TL structure. It was found that the equivalent circuital model (implemented in Matlab), with parameter extracted by optimization, yelds an acceptable approximation of the CRLH TL responses obtained by fullwave elctromagnetic simulation (implemented in Sonnet) on a wide bandwidth.
