19 results on '"Fernández Pantoja, Mario"'
Search Results
2. Design of coils for lateralized TMS on mice
- Author
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Cobos Sánchez, Clemente, primary, Jurado García, José Joaquín, additional, Ruiz Cabello, Miguel, additional, and Fernández Pantoja, Mario, additional
- Published
- 2020
- Full Text
- View/download PDF
3. Optimization of Far-field Radiation from Impedance Loaded Nanoloops Accelerated by an Exact Analytical Formulation
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Nagar, J., Chaky, R. J., Fernández Pantoja, Mario Alberto, McKinley, A., and Werner, D. H.
- Abstract
Impedance loading is a common technique traditionally used in the RF to enhance the performance of an antenna, but its application in the optical regime is not as rigorously studied. This is mainly due to a lack of exact analytical expressions that can be used to rapidly predict the radiation properties of loaded nanoantennas. This paper will derive a set of useful analytical expressions for the far-field radiation properties of loop antennas loaded with an arbitrary number of lumped impedances that are valid from the RF to optical regimes. The analytical expressions will be validated with full-wave solvers and can be evaluated more than 100x faster. The ability to perform such rapid evaluations enables, for the first time, large-scale single- and multi-objective optimizations. A series of optimizations reveal that electrically small super-directive antennas can be achieved at a variety of far field angles through capacitive loading, paving the way for a pattern reconfigurable antenna. In addition, gains of greater than 3 dB can be achieved for electrically small antennas over a fractional bandwidth of 28%. Finally, it is shown that impedance loading can be used to achieve circularly polarized radiation from a single loop., Paper submitted for review on 03/20/2018. The authors would like to acknowledge the Spanish Ministry of Education - Commission Fulbright Program “Salvador de Madariaga” (PRX14/00320) for sponsoring the joint research collaboration. This work has also been partially financed by the Spanish and Andalusian research programs TEC202016-79214-C3-3-R and P12-TIC-1442 as well as by the Center for Nanoscale Science, an NSF Materials Research Science and Engineering Center, under the award DMR-1420620.
- Published
- 2019
4. Numerical assessment in aeronautics for electromagnetic environmental effects
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Ruiz Cabello Núñez, M. D., Fernández Romero, S., Pous Solà, M., Poyatos Martínez, David, Fernández Chimeno, M., Gutierrez, Guadalupe G., Rubio Bretones, Amelia, Añón Cancela, M., Ferran, Silva, Álvarez, Jesús, Fernández Pantoja, Mario, Nuño, Luis, Gómez Martín, Rafael, Escot Bocanegra, David, Rui Costa, Pere J., Trallero, Rafael, Jauregui Telleria, Ricardo I., González García, Salvador, Pous Solà, M. [0000-0003-2660-5254], Silvia Martínez, F. [0000-0003-3019-3993], Fernández Chimeno, M. [0000-0001-8384-1320], and Rui Costa, P. J. [0000-0003-0477-1972]
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Electrical and electronic Systems ,Aeronautics ,E3 Certification - Abstract
Modern aircrafts have become increasingly dependent on electronic equipment to control its systems. This has led to new safety concerns with respect to their immunity levels against EM hazards and, in consequence, their assessment by aircraft manufacturers. Besides, the variety of potential EMI sources are increasing dramatically due to the appearing of new artificial sources in addition to the natural ones. This situation is aggravated by the pervasive use of composite materials in aircraft structure: CFC, CFRC, CFRP, etc. These materials, lighter and stronger from the mechanical point of view, are poorer conductors than metals and therefore have lower shielding capabilities. From the EMC point of view, the main EM threats for an AV can be summarized as follows: • Lightning Indirect Effects (LIE): 0 to ~50 MHz: Indirect effects are caused by the electric current flowing through the structure and internal wiring as a consequence of the impact of a lightning strike. This is, undoubtedly, the most important threat to onboard electronic equipment, becoming critical for aircrafts mostly made of CFCs (Meyer et al., 2008) like, for instance, modern UAVs. • High Intensity Radiated Fields (HIRF): 0 to ~100 MHz: This threat is caused by artificial intentional or unintentional, external or internal RF sources. These are constantly increasing in number: TV, mobile networks (3G/4G/5G), radars, navigation satellite systems, etc. and may couple to cables and equipment, potentially causing malfunction for high field levels. • Electromagnetic Pulses (EMP) of Nuclear or Non-Nuclear Origin: 0-100 MHz: Most of current non-nuclear low-level electromagnetic pulse generators are not capable of radiating enough EM energy to produce a significant damage. However, novel devices are appearing, which are able to involve much higher power levels with extremely short durations. These modern weapons, also named E-bombs, are becoming cheaper and susceptible of being used in terrorist acts. They can wreak havoc on computers and networks, yielding temporary disruptive effects (Radasky et al., 2004; Radasky, 2014). In all these cases, as a result of the exposition to the EM hazard, transient currents will flow along the aircraft surface, creating EM fields which penetrate into the fuselage through apertures such as windows, or by diffusion through parts made of poorly conducting materials (Figure 1). Inside the aircraft, these transients induce currents to the EWIS, which, in turn, couple to equipment, potentially compromising their safe operation or even creating permanent damage. Several aviation incidents, reported in the last quarter of the past century, triggered the attention of aviation agencies to include strict EMC requirements for the airworthiness certification processes of AVs during their whole life-cycle. Before a newly developed AV model is permitted to operate, it must get a certificate of airworthiness issued by an aviation regulatory authority. For instance, in civil aviation, the regulatory authority is the EASA in the EU, or the FAA in the US. Within the EMC context, certification methods are mainly based on experimental tests and the guidelines provided in several standardized documents and certification guides: Eurocae ED-105/SAE-ARP5416; SAE-ARP5415; Eurocae ED-107/SAE-ARP5583; MIL-STD-202; MIL-STD-461;EUROCAE ED-14/RTCA/DO-160, MIL-STD-464, STANAG 4370, etc.. Electrical and electronic systems on board air vehicles are susceptible to electromagnetic interference (EMI). This has made the topic of electromagnetic compatibility (EMC), a major concern for aircraft safety. The use of composite materials worsens this situation, for their poor shielding and low conductive capabilities. Some of the main experimental E3 certification scenarios used in aeronautics are revisited in this chapter. Guidelines to achieve simple, yet accurate, numerical models of them are provided, with appropriate tradeoffs between computational simplicity and accuracy. The numerical method, endowed with extended capabilities, has been chosen for this task for its ability and efficiency to deal with complex problems of arbitrary materials. The feature selective validation (FSV) IEEE standard procedure, commonly used to quantify the comparison of data in electromagnetic problems, is also revisited. The simulation of three different air vehicles in several certification scenarios is finally described and the numerical results compared to experimental data. Peerreview
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- 2018
5. SIVA: A benchmark for numerical validation of composite UAV modeling
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Ruiz Cabello, Miguel, González García, Salvador, Pous, Marc, Pascual Gil, Enrique, Díaz Angulo, Luis Manuel, López, Patricia, Riu, Pere J., Mateos, Daniel, Poyatos, David, Fernández, Mireya, Álvarez, Jesús, Gutiérrez, Guadalupe G., Fernández Pantoja, Mario Alberto, Añón, Manuel, Silva, Ferrán, Rubio Bretones, Amelia Consuelo|||0000-0002-9337-9093, Trallero, Rafael, Nuño, Luis, Escot, David, and Gómez Martín, Rafael Antonio|||0000-0003-0992-8369
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Software verification and validation ,Aerospace simulation ,Finite-difference methods ,Numerical analysis - Abstract
The increased use of carbon-fiber composites in unmanned aerial vehicles is a challenge for their EMC assessment by numerical solvers. For accurate and reliable simulations, numerical procedures should be tested not only for individual com- ponents, but also within the framework of complete systems. With this aim, this paper presents a benchmark test case based on experimental measurements coming from direct-current injection tests in the SIVA unmanned air vehicle, reproduced by a numerical finite-difference-time-domain solver that employs a new subgrid- ding scheme to treat lossy composite thin panels. Validation was undertaken by applying the feature selective validation method, which quantifies the agreement between experimental and numerical data., This work was supported by the Projects TEC2013-48414- C3- { 1,2,3 } -R, TEC2016-79214-C3- { 1,2,3 } -R, and TEC2015-68766-REDC (Spanish MINECO, EU FEDER), P12-TIC-1442 (J. de Andalucia, Spain), Alhambra-UGRFDTD (AIRBUS DS), and by the CSIRC alhambra.ugr.es supercomputing center.
- Published
- 2017
6. Computational Modeling of Graphene and Carbon Nanotube Structures at Infrared and Optical Regimes
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Fernández Pantoja, Mario Alberto, Mateos Romero, Daniel, Lin, Hai, Werner, Douglas H., and González García, Salvador
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- 2015
7. A Nodal Hybrid Continuous-Discontinuous Galerkin Time Domain Method for Maxwell’s Curl Equations
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Díaz Angulo, Luis Manuel, Alvarez Gonzalez, Jesús, Teixeira, Fernando, Fernández Pantoja, Mario Alberto, and González García, Salvador
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Maxwell's equations ,Discontinuous Galerkin method ,Discontinuous Galerkin time-domain ,Continuous-discontinuous Galerkin time-domain ,Continuous Galerkin method - Abstract
A new nodal hybrid continuous-discontinuous Galerkin time-domain (CDGTD) method for the solution of Maxwell's curl equations is proposed and analyzed. This hy- bridization is made by clustering small collections of elements with a continuous Galerkin (CG) formalism. These cluste rs exchange information with their exterior through a discontinuous Galerkin (DG) numerical flux. This scheme shows reduced numerical dis- persion error with respect to classical DG formul ations for certain orders and numbers of clustered e lements. The spectral radius of the clustered semi-discretized operator is smaller than its DG counterpart allowing for larger time steps in e xplicit time integra- tors. Additionally, the continuity across the element boundaries allows us a reduction of the number of degrees of freedom of up to about 80% for a low-order three-dimensi onal implementation., This work was supported in part by the National Projects under Grant TEC2010-20841-C04-04, Grant TEC2013- 48414-C3-1-R, Grant CSD2008-00068, Grant P09-TIC-5327, and Grant P12- TIC-1442, the GENIL Excellence Network, and the National Science Founda- tion under Grant ECCE-1305838
- Published
- 2015
8. Time-domain numerical modeling of THz photoconductive antennas
- Author
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Moreno, Enrique, Fernández Pantoja, Mario Alberto, González García, Salvador, Rubio Bretones, Amelia Consuelo|||0000-0002-9337-9093, and Gómez Martín, Rafael Antonio|||0000-0003-0992-8369
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Semiconductor device modeling ,Photo- conductive antennas ,Finite-difference time-domain ,Terahertz sources - Abstract
This paper presents a computational procedure to simulate the time-domain behavior of photoconductive antennas made of semiconductor and metal materials. Physical modeling of semiconductor devices at terahertz regime can be achieved by applying joint electronic and electromagnetic procedures, e.g., solving a coupled system of equations inferred from Poisson’s drift-diffusion and Maxwell’s equations. A set of discrete equations are derived by applying a combined finite-difference methodology for the previous steady-state and the finite-difference time-domain procedure for the transient regime. The results for the radiated electric field at broadside direction show good agreement with the experimental results previously reported in the literature, This work was supported in part by the Spanish Ministry of Education under Project CSD2008-00068, the Junta de Andalucia Project P09-TIC-5327, the EU FP7/2007-2013, under grant 205294 (HIRF-SE project), and the Spanish National Project TEC2010-20841-C04-04
- Published
- 2014
9. An Explicit Nodal Space-Time Discontinuous Galerkin Method for Maxwell’s Equations
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Alvarez Gonzalez, Jesus, Fernández Pantoja, Mario Alberto, González García, Salvador, and Díaz Angulo, Luis Manuel
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Computational Electrodynamics ,MathematicsofComputing_NUMERICALANALYSIS ,Space-Time Discontinuous Galerkin ,Discontinuous Galerkin Methods - Abstract
A novel implicit nodal Space-Time Discontinuous Galerkin (STDG) method is proposed in this paper. An eigenvalue analysis is performed and compared with that for a DG scheme solved with a 4th-Order Runge-Kutta time integrator. We show that STDG offers a significant improvement of dissipative and dispersive properties and allows larger time steps, regardless of the spatial hp-refinement. A domain-decomposition technique is used to introduce an explicit formulation of the method in order to render it computationally efficient., This work is partially funded by the National Projects TEC2010-20841- C04-04, TEC2013-48414-C3-01, CSD2008-00068, P09-TIC-5327, P12-TIC- 1442, and from the GENIL excellence network.
- Published
- 2014
10. A comparison of the performance of THz photoconductive antennas
- Author
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Moreno, Enrique, Fernández Pantoja, Mario Alberto, Rubio Bretones, Amelia Consuelo, Ruiz Cabello, Miguel, and González García, Salvador
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Terahertz technology ,Physics::Optics ,Photoconductive antennas - Abstract
This letter explores the influence of the geometry of bias electrodes in the performance of terahertz (THz) photoconductive antennas (PCAs). To this end, a methodology is presented to calculate numerically the operational bandwidth and radiation efficiency of the PCAs. The procedure is validated through a comparison to experimental measurements. Also, results are depicted from numerical simulations of different PCAs under varying conditions of bias voltage, doping factor, and incident optical power. It is concluded that an appropriate con figuration of the electrodes may double the efficiency of the antennas, with a penalty in the bandwidth of the radiated pulse usually smaller than 10%., This work was supported in part by the Spanish Ministry of Education under Project CSD2008-00068, the Junta de Andalucia Project P09-TIC-5327, the EU FP7/2007-2013 under Grant 205294 (HIRF-SE project), and the Spanish National Project TEC2010-20841-C04-04
- Published
- 2014
11. GA design of small thin-wire antennas: comparison with Sierpinski-type prefractal antennas
- Author
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Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio, Fernández Pantoja, Mario, García Ruíz, Francisco Javier, Rubio Bretones, Amelia C., González García, S., Gómez Martín, Rafael A., González Arbesú, José María, Romeu Robert, Jordi, Rius Casals, Juan Manuel, Werner, P. L., Werner, Douglas H., Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio, Fernández Pantoja, Mario, García Ruíz, Francisco Javier, Rubio Bretones, Amelia C., González García, S., Gómez Martín, Rafael A., González Arbesú, José María, Romeu Robert, Jordi, Rius Casals, Juan Manuel, Werner, P. L., and Werner, Douglas H.
- Abstract
A new set of genetically generated electrically small thin-wire antennas with a better performance than that of several families of Sierpinsky prefractal monopoles of the same electrical size at resonance is presented, Peer Reviewed
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- 2006
12. GA design of wire pre-fractal antennas and comparison with other Euclidean geometries
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Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio, Fernández Pantoja, Mario, García Ruíz, Francisco Javier, Rubio Bretones, Amelia C., Gómez Martín, Rafael A., González Arbesú, José María, Romeu Robert, Jordi, Rius Casals, Juan Manuel, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio, Fernández Pantoja, Mario, García Ruíz, Francisco Javier, Rubio Bretones, Amelia C., Gómez Martín, Rafael A., González Arbesú, José María, Romeu Robert, Jordi, and Rius Casals, Juan Manuel
- Abstract
A multi-objective genetic algorithm (GA) has been applied in conjunction with the numerical electromagnetic code (NEC) to the optimization of wire pre-fractal Koch-like antennas in terms of bandwidth, efficiency, and electrical size. Their performance is compared to that of other nonfractal designs., Peer Reviewed
- Published
- 2003
13. GA Design of a Thin-Wire Bow-Tie Antenna for GPR Applications.
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Moreno De Jong Van Coevorden, Carlos, Rubio Bretones, Amelia, Fernández Pantoja, Mario, García Ruiz, Francisco J., García, Salvador G., and Gómez Martin, Rafael
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ALGORITHMS ,ANTENNAS (Electronics) ,GROUND penetrating radar ,RADIATION ,DIPOLE moments - Abstract
A microgenetic algorithm has been applied to design a new ultrawideband thin-wire bow-tie antenna for ground-penetrating radar applications. The broadband performance of the antenna is achieved by resistive loading and by optimizing the number of wires and the angular distances between those wires. The radiation characteristics of the optimized antenna are discussed, and its performance is compared to that of a restively loaded Wu-King dipole. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
14. GA design of small thin-wire antennas: comparison with Sierpinski-type prefractal antennas
- Author
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Fernández Pantoja, Mario, García Ruíz, Francisco Javier, Rubio Bretones, Amelia C., González García, S., Gómez Martín, Rafael A., González Arbesú, José María|||0000-0002-9601-0988, Romeu Robert, Jordi|||0000-0003-0197-5961, Rius Casals, Juan Manuel|||0000-0003-0606-5422, Werner, P. L., Werner, Douglas H., Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, and Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio
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GA design ,Monopole antennas ,Optimització matemàtica ,Mathematical optimization ,sense organs ,macromolecular substances ,Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica [Àrees temàtiques de la UPC] ,Genetic algorithms ,Thin-wire antennas ,Resonance frequency ,Antennas (Electronics) Design and construction ,Antenes (Electrònica) -- Disseny i construcció ,Fractal antennas - Abstract
A new set of genetically generated electrically small thin-wire antennas with a better performance than that of several families of Sierpinsky prefractal monopoles of the same electrical size at resonance is presented
15. GA design of wire pre-fractal antennas and comparison with other Euclidean geometries
- Author
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Fernández Pantoja, Mario, García Ruíz, Francisco Javier, Rubio Bretones, Amelia C., Gómez Martín, Rafael A., González Arbesú, José María, Romeu Robert, Jordi, Rius Casals, Juan Manuel, Universitat Politècnica de Catalunya. Departament de Teoria del Senyal i Comunicacions, and Universitat Politècnica de Catalunya. ANTENNALAB - Grup d'Antenes i Sistemes Radio
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Genetic algorithms design ,Monopole antennas ,GA ,NEC ,Electrically small antennas ,Efficiency ,Enginyeria de la telecomunicació::Radiocomunicació i exploració electromagnètica [Àrees temàtiques de la UPC] ,Euclidean geometries ,Antenes (Electrònica) -- Disseny i construcció ,Fractal antennas ,Kock-like antennas ,Bandwidth ,Hardware_GENERAL ,Wire antennas ,Electrical size ,Numerical electromagnetic code ,Antennas (Electronics) ,Multiobjective genetic algorithm ,UHF antennas - Abstract
A multi-objective genetic algorithm (GA) has been applied in conjunction with the numerical electromagnetic code (NEC) to the optimization of wire pre-fractal Koch-like antennas in terms of bandwidth, efficiency, and electrical size. Their performance is compared to that of other nonfractal designs.
16. Time domain discontinuous galerkin methods for mexwell equations
- Author
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Díaz Angulo, Luis Manuel, Álvarez González, Jesús, Fernández Pantoja, Mario Alberto, González García, Salvador, Universidad de Granada. Departamento de Electromagnetismo y Física de la Materia, and Fernández Pantoja, Mario
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Elementos discontinuos de Galerkin ,Propagación ,Ecuaciones ,Ondas electromagnéticas - Abstract
Tesis Univ. Granada. Programa Oficial de Doctorado en: Física y Matemáticas, The work described in this dissertation has been partially funded through the European Community's Seventh Framework Programme FP7/2007-2013, under grant agreement n. 205294 (HIRF SE project), and his work is partially funded by the National Projects TEC2010-20841-C04-04, TEC2013-48414-C3-01, CSD2008-00068, P09-TIC-5327, P12-TIC-1442, and from the GENIL excellence network.
- Published
- 2015
17. Diseño optimizado de antenas mediante algoritmos genéticos
- Author
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Moreno de Jong, Carlos, Universidad de Granada. Departamento de Electromagnetismo y Física de la Materia, Gómez Martín, Rafael, Fernández Pantoja, Mario, Gómez Martín, Rafael Antonio, and Fernández Pantoja, Mario Alberto
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Antenas ,Electromagnetismo ,Algoritmos genéticos - Abstract
Resumen y Conclusiones en inglés, Tesis Univ. Granada. Departamento de Electromagnetismo y Física de la Materia. Leída el 5 de junio de 2008
- Published
- 2011
18. Nuevos diseños de antenas pequeñas de hilo mediante algoritmos genéticos y geometría prefractal
- Author
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García Ruiz, Francisco Javier, Rubio Bretones, Amelia Consuelo, Fernández Pantoja, Mario Alberto, Universidad de Granada. Departamento de Electromagnetismo y Física de la Materia, Rubio Bretones, Amelia, and Fernández Pantoja, Mario
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Antenas (Telecomunicación) ,Electromagnetismo ,Algoritmos genéticos - Abstract
Tesis Univ. Granada. Departamento de Electromagnetismo y Física de la Materia. Leída el 9 de mayo de 2005
- Published
- 2005
19. Algoritmos orientados al estudio y modelado de dispositivos electromagnéticos en el rango de los terahercios
- Author
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Moreno Pérez, Enrique, Rubio Bretones, Amelia Consuelo, Fernández Pantoja, Mario Alberto, and Universidad de Granada. Departamento de Química Física
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Ondas submilimétricas ,Dispositivos electromagnéticos ,Algoritmos ,Antenas ,Métodos de simulación ,537.8 - Abstract
Tesis Univ. Granada. Departamento de Química Física, Este trabajo ha sido financiado por los siguientes proyectos "Terahertz technology for electromagnetic sensing applications", Ministerio de Ciencia e Innovación, y "Teralab: numerical laboratory for design and simulation of THz technology", Junta de Andalucía.
- Published
- 2018
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