Novos procedimentos de análise para linhas de transmissão.

Abstract

The characteristics of circular cylindrical microstrip lines and backed slotlines are investigated. The analysis was developed in two steps. A quasi-TEM model was considered in the first step, while a fullwave model was assumed, in the second step. The quasi-TEM analysis was performed by using variational and moment methods, single and coupled cylindrical microstrip lines, in the spectral domain. The fullwave analysis was developed for single cylindrical microstrip lines, by considering a combinations of the Hertz vector potenciais, Parseval's theorem and Galerkin's method. In the fullwave analysis, lossless dielectric layers were assumed and the characteristics of higher order propagation modes were obtained. The coaxial backed slotlines structure is also considered. The fullwave analysis is developed by using the same technique employed in the study of cylindrical microstrip structures. A numerical analysis was developed in order to obtain results for the propagation mode characteristics in single microstrips and backed slotlines, as functions of their geometries. The analysis of coupled microstrip lines was also performed. Agreement with the results available in the literature for several particular cases, such as microstrip and planar backed slotlines, was observed. The analysis presented in this work is general, accurate and can be easily extended to investigation/analyse other transmission lines such as those obtained when considering anisotropic dielectric/ferrimagnetic multilayers with/without overlays.