Sebastian Lauro

Symmetrical Coupled Microstrip Lines With Epsilon Negative Metamaterial Loading

In this paper, we show how metallic plate inclusions can be used to enhance the coupling values of microstrip directional couplers. The analysis and the design of symmetrical coupled microstrip lines with high values of forward-wave coupling with a coupling length very small are presented. A quasi-static circuit model of the structure is developed and physical insights on the operation of the proposed component and on the role of Epsilon NeGative (ENG) material slab loading are also given. Full wave numerical simulations are shown for different geometries.

Efficient Modeling of the Crosstalk Between Two Coupled Microstrip Lines Over Nonconventional Materials Using an Hybrid Technique

In this contribution, we present a proper extension of the finite-element method based on a variational formulation which is able to take into account the effects of nonconventional materials in the evaluation of the electromagnetic field inside a cavity bounded by both closed and open boundary conditions. As a numerical application, we show how nonconventional materials like, for instance, metamaterials can be used in the design of integrated circuits, in order to reduce the proximity effects among planar transmission lines.

Coupled microstriplines with ENG metamaterial loading: physical concepts, design formulas, and numerical simulations

In this contribution, we present the analysis and design of coupled microstriplines loaded with proper epsilon negative (ENG) metamaterial slabs. The behavior of the proposed component is at first analyzed through a heuristic approach. The main result of this investigation is that, depending on the orientation of the ENG slab, it is possible to achieve either higher or very reduced coupled values. A conformal mapping technique is, then, applied in order to derive closed analytical forms for the effective permittivity and the mutual coupling as a function of the geometrical and electrical parameters for the different orientations of the ENG slab. Such formulas are used to design different components, such as power dividers, decoupled lines, coupled lines with anomalous values of coupling, etc. Finally, the electromagnetic behavior of these components expected from the analytical design has been compared to the one obtained through full-wave numerical simulations, showing a very good agreement.

Enhanced coupling values in coupled microstriplines using metamaterials

In this paper, we show how metamaterials can be used to enhance the coupling values of micros trip directional couplers. Coupling between regular coplanar microstrip lines, in fact, is limited, due to the small ratios between the characteristic impedances of even and odd TEM modes supported by the structure. The broadside configuration or the employment of an overlay are often utilized to overcome this limitation, leading, however, to more bulky components. On the other hand, the employment of metamaterials with a negative real part of the permittivity is able to increase the coupling values, while keeping the profile of the structure very low. A quasi-static model of the structure is developed and physical insights on the operation of the proposed component and on the role of the metamaterial loading are also given. Simple design formulae derived through a conformal mapping technique are presented and validated through proper full wave numerical simulations.

Metamaterials as complex dielectrics in the design of a new class of integrated circuits

In this paper, we show how metamaterials can be used either to enhance the coupling values or to reduce the crosstalk between the strips of coupled microstriplines. Coupling between regular coplanar microstriplines, in fact, is limited, due to the small ratios between the characteristic impedances of even and odd TEM modes supported by the structure. The broadside configuration or the employment of an overlay are often utilized to overcome this limitation, leading, however, to more bulky components. On the other hand the coupling/crosstalk can be undesiderable in printed circuits. The employment of metamaterials with a negative real part of the permittivity is able to increase or decrease the coupling values, while keeping the profile of the structure very low. A quasi-static model of the structure is developed and physical insights on the operation of the proposed components and the role of the metamaterial loading are also given. Finally numerical results are shown for two proposed layouts.

BEM analysis of electromagnetic components filled with unconventional materials

Purpose – To devise a parametric study using a new application of the boundary element method (BEM) and to propose an efficient approach for speeding up the computation time of the BEM based on neural networks (NNs).Design/methodology/approach – A 3D finite elements formulation is combined with radial basis function NNs to speeding up the computation time.Findings – The paper shows how to estimate the role of thin slabs filled with unconventional media in order to increase the coupling values when placed between two metallic strips in a coupled microstrip line layout or to improve the shielding properties when used as absorber.Research limitations/implications – The numerical results here presented are not bianisotropic but can be easily extended to take into account bianisotropic media.Originality/value – The formulation is one of the only with the potential for investigating unconventional bianisotropic media like Chiral materials which are seen as one possible route to achieving double negative media.