Aplicação do método iterativo baseado no conceito de ondas (WCIP) na análise de antenas e circuitos planares multicamadas.

Abstract

This work presents the modeling and analysis of multilayer planar circuits for frequencies of a few GHz using an iterative method based on the wave concept (Wave Concept Iterative Procedure – WCIP). This method determines a simple relation between the incident and reflected waves in different media of each side of a discontinuity. The treatment of the field electromagnetic phenomena is formulated in two domains. The reflection is treated in the modal domain and the diffraction, defined from the continuity and boundaries conditions, in the space domain. A consideration of the fields’ propagation in a rectangular wave guide allows the application of a Fourier Transform and wave decomposition into TE and TM modes. A Fourier Modal Transform (FMT) is the basic tool in the iterative procedure; it allows to carry out the transformation between the two modes. An initial mathematical formulation is presented to allow the simulation of planar circuits. Finally, this formulation is expanded for multilayer planar circuits. Simulation results with the developed method for planar circuits and multilayer planar circuits (filter and slot coupled patch antenna) have been compared with measured and simulated results found in the literature. Finally, quasi-optical space power combining circuits are presented as well as multilayer amplifier structure based on the quasi-optical circuits concepts. Polarizers are placed perpendicularly between the input and the output of the structure and an active element for the amplification. The polarizers are considered as ideal and developed with the WCIP. Negative impedance is used for the amplification. The use of the auxiliary source method allows an electromagnetic modeling of the composed structure for passive and active elements.