1,122 research outputs found
Seminario interdisciplinario II
Documento PDF, 33 páginasGuía de estudio para el curso Seminario interdisciplinario II, código 0506, que imparte la Escuela de Ciencias Sociales y Humanidades de la UNED.Universidad Estatal a Distancia de Costa Ric
Seminario interdisciplinario I
Documento PDF, 22 páginasGuía de estudio para el curso Seminario interdisciplinario I, código 0504, que imparte la Escuela de Ciencias Sociales y Humanidades de la UNED.Universidad Estatal a Distancia de Costa Ric
Numerical implementation of the mixed potential integral equation for planar structures with ferrite layers arbitrarily magnetized
This work presents a new implementation of the mixed potential integral equation (MPIE) for planar structures that can include ferrite layers arbitrarily magnetized. The implementation of the MPIE here reported is carried out in the space domain. Thus it will combine the well-known numerical advantages of working with potentials as well as the flexibility for analyzing nonrectangular shape conductors with the additional ability of including anisotropic layers of arbitrarily magnetized ferrites. In this way, our approach widens the scope of the space domain MPIE and sets this method as a very efficient and versatile numerical tool to deal with a wide class of planar microwave circuits and antennas.Ministerio de Educación y Ciencia TEC2004-0321
Citizenry, internet and political behaviour. Digital natives within the Spanish political system
La participación en los movimientos de protesta, la implicación en nuevos partidos, el apoyo a candidatos outsider o el voto está protagonizado por una nueva generación de nativos digitales, cuyo comportamiento político está determinado en gran parte por el acceso y uso de los nuevos medios
Spectral and variational analysis of generalized cylindrical and elliptical strip and microstrip lines
The variational technique in the spectral domain (VTSD) is shown to be an efficient method for computing the quasi-TEM parameters of arbitrary multiconductor and multidielectric cylindrical or elliptical strip configurations. Simple conformal mappings reduce the cylindrical or elliptical geometries to an equivalent rectangular one with periodic boundary conditions. The analysis of this equivalent structure is achieved by taking advantage of previous work on boxed planar structures. The numerical convergence of the programs is greatly accelerated, incorporating the asymptotic behavior of the series appearing in the analysis in such a way that efficient programs have been written. It is pointed out that excessively simple approximations to the surface charge distribution yield meaningful numerical errors, mainly when strong coupling or wide strips are involved. As an application example, the behavior of the characteristic parameters of asymmetric coupled structures on multilayer substrates is shown
Comments on "Internal impedance of conductors of rectangular cross section"
The alternate current (ac) internal impedance of rectangular cross-sectional conductors used as transmission lines and interconnects in microwave and digital printed circuits were analyzed. The difference between the real and imaginary parts of internal impedance to the existence of right-angle corners in the rectangular cross-sectional geometrics were studied. The corners are responsible for the nonconstant distribution of the currents along the periphery of the conductors. The consideration of incremental inductance was correlated to nonperfect nature of the conductors rather than internal inductance
A suitable integral equation for the quasi-TEM analysis of hybrid strip/slot-like structures
This paper reports on a suitable formulation of the spectraldomain/integral-equation method for the quasi-TEM analysis of hybrid strip/slot-like planar lines. The free surface charge distribution is used as an unknown on the strip-like interface, whereas the electric field is used on the slot-like region. This formulation allows us to reduce the number of basis functions and makes possible a unified treatment of the problem. A single type of basis functions is used, leading to a quasi-analytical evaluation of the Galerkin matrix entries. The performance of the method is illustrated with a practical example structure useful for coupler design
Capacitance and Inductance Matrices for Multistrip Structures in Multilayered Anisotropic Dielectrics
In this paper we present a unified variational approach to determine the capacitance and inductance matrices of generalized multistrip systems embedded in a multilayered iso/anisotropic dielectric lossless medium. The analysis is carried out in the spectral domain to take advantage of previously obtained recurrence relations which calculate the Green's function in the spectral domain. The method leads to a low-order system of linear equations, which is shown explicitly. Examples and comparison with previously published results have been included
Quasi-Analytical Static Solution of the Boxed Microstrip Line Embedded in a Layered Medium
In this paper, a quasi-analytical method is presented to carry out the quasi-TEM study of a microstrip line embedded in a general layered substrate with rectangular enclosure. Electric walls, magnetic walls and periodic boundary conditions are considered. The analysis is based on the spectral domain formulation and the use of a proper expansion of the free charge distribution (Chebyshev polynomials with edge condition). Two different approaches are proposed to speed up the evaluation of the spectral series in such a way that only a few spectral terms must be retained in the numerical computations of the mentioned series. The propagation parameters and the charge distribution are obtained with extreme accuracy in fractions of one second on a personal computer
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