Showing papers by "Francisco Medina published in 1986"

Multilayer Planar Structures for High-Directivity Directional Coupler Design

Abstract: One of the problems that appears in the directional couplers designed with nonhomogeneous coupled transmission lines (CTL's) is their inherently poor directivity, due to the difference between the mode phase velocities. In order to overcome this defect, several multilayer configurations for high-directivity coupler design are proposed and studied in this paper. The analysis has been achieved by means of variational techniques in the spectral domain. A computer program to generate optimum design curves has been written, and several examples for certain dielectric materials are included. On the basis of these curves, various directional coupler designs are presented and discussed.

Accurate Approach for Computing Quasi-Static Parameters Off Symmetrical Broadside-Coupled Mlcrostrips in Multilayered Anisotropic Dielectrics

Abstract: In this paper, we present a method for calculating the propagation parameters of shielded broadside- end broadside edge-coupled microstrip transmission lines. Conductor strips are assumed to be embedded in a multilayered isotropic and/or anisotropic medium. This method provides accurate expressions for computing upper and lower bounds for the true values of mode capacitances, The effects of side wall-shielding and anisotropy of the material are investigated. Some particular multilayered structures are analyzed, which could be applied to the design of directional couplers and filters.

Multilayer Planar Structures for High Directivity Directional Coupler Design

Abstract: One of the problems that appear in the directional couplers designed with coupled transmission lines embedded in nonhomogeneous medium is their poor directivity In this work several multilayer configurations for high directivity coupler design are studied by means of a variational technique in the spectral domain, and a set of curves for an optimum design are included