The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform

Jorge A Ruizcruz - One of the best experts on this subject based on the ideXlab platform.

  • algorithmic implementation of a hybrid 2d finite element mode matching method based on Nested Function spaces
    European Conference on Antennas and Propagation, 2019
    Co-Authors: Juan Corcoles, Jorge A Ruizcruz, Raul Harobaez
    Abstract:

    This work reports an algorithmic implementation of a hybrid finite element (FE) – mode matching technique based on the concept of Nested 2D FE Function spaces, suited to analyze waveguide components with diverse geometries as for instance transformers or polarizers for antenna feeds. Thanks to this technique, the inner cross product matrix in the mode matching method is readily built from precomputed FE matrices, which are already available from the mode computation in irregularly shaped cross-sections. Thus, this work focuses on the implementation of this technique such that critical steps are carried out in an efficient way (i.e. sparse matrix-vector products, vector-vector dot products, etc.). To that effect, a very powerful and flexible FE open source computing platform, namely FEniCS, along with its high-level Python interface, has been used.

  • Nested 2d finite element Function spaces formulation for the mode matching problem of arbitrary cross section waveguide devices
    Applied Mathematical Modelling, 2018
    Co-Authors: Juan Corcoles, Ana Moranlopez, Jorge A Ruizcruz
    Abstract:

    Abstract A large class of microwave, millimeter-wave and terahertz waveguide devices for high-frequency electronic systems are made up of waveguide steps cascaded along the propagation direction, giving rise to diverse modal and numerical analysis techniques to solve Maxwell equations for this problem. In this paper, a novel formulation is proposed to compute the numerical modes in all arbitrary cross-sections and characterize all waveguide steps involved in this kind of structures with a modular and straightforward approach through block-matrix operations. The key idea is expressing the modal fields in terms of 2D Nested Function spaces (each one for a different cross-section) made up of finite-element basis Functions. This leads to finite-element matrices used to compute the modes in all different arbitrary waveguides of the structure from a single inter-cross-section conforming 2D mesh. Moreover, these finite-element matrices and results are used to build directly the mode-matching solution of all steps in the structure. After comparison with analytical results for canonical steps, this flexible and efficient approach is validated with various examples of waveguide devices (two filters, a polarizer, a transformer and a polarization rotator), showing excellent agreement with other numerical methods and measurements.

Juan Corcoles - One of the best experts on this subject based on the ideXlab platform.

  • algorithmic implementation of a hybrid 2d finite element mode matching method based on Nested Function spaces
    European Conference on Antennas and Propagation, 2019
    Co-Authors: Juan Corcoles, Jorge A Ruizcruz, Raul Harobaez
    Abstract:

    This work reports an algorithmic implementation of a hybrid finite element (FE) – mode matching technique based on the concept of Nested 2D FE Function spaces, suited to analyze waveguide components with diverse geometries as for instance transformers or polarizers for antenna feeds. Thanks to this technique, the inner cross product matrix in the mode matching method is readily built from precomputed FE matrices, which are already available from the mode computation in irregularly shaped cross-sections. Thus, this work focuses on the implementation of this technique such that critical steps are carried out in an efficient way (i.e. sparse matrix-vector products, vector-vector dot products, etc.). To that effect, a very powerful and flexible FE open source computing platform, namely FEniCS, along with its high-level Python interface, has been used.

  • Nested 2d finite element Function spaces formulation for the mode matching problem of arbitrary cross section waveguide devices
    Applied Mathematical Modelling, 2018
    Co-Authors: Juan Corcoles, Ana Moranlopez, Jorge A Ruizcruz
    Abstract:

    Abstract A large class of microwave, millimeter-wave and terahertz waveguide devices for high-frequency electronic systems are made up of waveguide steps cascaded along the propagation direction, giving rise to diverse modal and numerical analysis techniques to solve Maxwell equations for this problem. In this paper, a novel formulation is proposed to compute the numerical modes in all arbitrary cross-sections and characterize all waveguide steps involved in this kind of structures with a modular and straightforward approach through block-matrix operations. The key idea is expressing the modal fields in terms of 2D Nested Function spaces (each one for a different cross-section) made up of finite-element basis Functions. This leads to finite-element matrices used to compute the modes in all different arbitrary waveguides of the structure from a single inter-cross-section conforming 2D mesh. Moreover, these finite-element matrices and results are used to build directly the mode-matching solution of all steps in the structure. After comparison with analytical results for canonical steps, this flexible and efficient approach is validated with various examples of waveguide devices (two filters, a polarizer, a transformer and a polarization rotator), showing excellent agreement with other numerical methods and measurements.

Ana Moranlopez - One of the best experts on this subject based on the ideXlab platform.

  • Nested 2d finite element Function spaces formulation for the mode matching problem of arbitrary cross section waveguide devices
    Applied Mathematical Modelling, 2018
    Co-Authors: Juan Corcoles, Ana Moranlopez, Jorge A Ruizcruz
    Abstract:

    Abstract A large class of microwave, millimeter-wave and terahertz waveguide devices for high-frequency electronic systems are made up of waveguide steps cascaded along the propagation direction, giving rise to diverse modal and numerical analysis techniques to solve Maxwell equations for this problem. In this paper, a novel formulation is proposed to compute the numerical modes in all arbitrary cross-sections and characterize all waveguide steps involved in this kind of structures with a modular and straightforward approach through block-matrix operations. The key idea is expressing the modal fields in terms of 2D Nested Function spaces (each one for a different cross-section) made up of finite-element basis Functions. This leads to finite-element matrices used to compute the modes in all different arbitrary waveguides of the structure from a single inter-cross-section conforming 2D mesh. Moreover, these finite-element matrices and results are used to build directly the mode-matching solution of all steps in the structure. After comparison with analytical results for canonical steps, this flexible and efficient approach is validated with various examples of waveguide devices (two filters, a polarizer, a transformer and a polarization rotator), showing excellent agreement with other numerical methods and measurements.

Raul Harobaez - One of the best experts on this subject based on the ideXlab platform.

  • algorithmic implementation of a hybrid 2d finite element mode matching method based on Nested Function spaces
    European Conference on Antennas and Propagation, 2019
    Co-Authors: Juan Corcoles, Jorge A Ruizcruz, Raul Harobaez
    Abstract:

    This work reports an algorithmic implementation of a hybrid finite element (FE) – mode matching technique based on the concept of Nested 2D FE Function spaces, suited to analyze waveguide components with diverse geometries as for instance transformers or polarizers for antenna feeds. Thanks to this technique, the inner cross product matrix in the mode matching method is readily built from precomputed FE matrices, which are already available from the mode computation in irregularly shaped cross-sections. Thus, this work focuses on the implementation of this technique such that critical steps are carried out in an efficient way (i.e. sparse matrix-vector products, vector-vector dot products, etc.). To that effect, a very powerful and flexible FE open source computing platform, namely FEniCS, along with its high-level Python interface, has been used.

J. Laird - One of the best experts on this subject based on the ideXlab platform.

  • IOS Press On the Expressiveness of Affine Programs with Non-local Control: The Elimination of Nesting in SPCF
    2014
    Co-Authors: J. Laird
    Abstract:

    Abstract. We use a denotational semantics to show that every term in SPCF (a typed Functional language with simple non-local control operators) is contextually equivalent to one which is typable in an affine typing system. Nested Function calls and recursive definitions are not affinely typable, and so our result entails that they can be eliminated from SPCF without losing expressiveness. Our proof is based on the observation of Longley that every type of SPCF is a retract of a first-order type. We describe retractions of this kind in bistable biorder models of SPCF which are definable in the affine fragment. This allows us to transform an arbitrary SPCF term into an affine one by mapping it to a first-order term, obtaining an (affine) “normal form”, and then projecting back to the original type. We show the flexibility of our approach by considering two variants of SPCF, a finitary, call-by-name version and a call-by-value version over the natural numbers. In the infinitary case, (in which we establish in addition that all instances of recursive definition may be replaced with iteration) our proof is based on an analysis of the relationship between SPCF definable Functions and strategies for computing them sequentially. 1