LARGE TRANSFORMATION-RATIO MULTILAYERED PLANAR TRANSMISSION LINE TRANSFORMERS USING HIGH-DIELECTRIC-CONSTANT THIN FILM
Keywords:Impedance matching, transmission line transformer, CPW, very high dielectric constant films
A new configuration to implement wide-band transmission line impedance transformers with large transformation ratios and compact size is proposed. This novel multilayered structure consists of a very high-dielectric-constant film layer over conventional bulk substrates. In order to illustrate the advantage of this new configuration, a 1.6-cm long transmission line impedance transformer was designed and its performance was analyzed using the finite element method. The superior performance of the structure was confirmed through comparison with previous structures from the literature for a planar transmission line transformer from 50Â ï—Â to 8Â ï—. An impedance transformer from 50Â ï—Â to 3.5Â ï—Â designed in the new structure was demonstrated, and for the first time such low impedance transformation level could be achieved. Using comfortable transversal dimensions, good return loss and very little dispersion were observed up to 40 GHz.
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