Ejemplo práctico de diseño de un filtro en iris rectangular empleando tecnología SIW para laboratorios docentes

Comunicación presentada en el XXIX Simposium Nacional de la Unión Científica Internacional de Radio, URSI 2014, Valencia, Septiembre 2014.This paper presents the design and practical implementation of a waveguide-based microwave filter in Substrate Integrated Waveguide (SIW) technology. The use of SIW technology for implementing waveguide filters makes the presented design specially aimed for being used in undergraduate courses related to microwave engineering and filter designing. Their low cost and easiness from the filter fabrication point of view allows their use in microwave laboratory courses where students can implement their own theoretical filter designs and measure their frequency response

Efficient methods for radiation, scattering and propagation. Poster

This document describes the research activities performed in the areas of antennas, scattering and wave propagation by several research groups belonging to different Universities located in Eastern Spain. These groups are working in the practical applications of efficient numerical electromagnetic methods within the frame of several research projects funded by private and public Spanish and European institutions. The main results obtained by these groups related to such topics, i.e. analysis algorithms, CAD tools, validation prototypes, as well as most relevant publications in technical conferences, journals and books, will be thoroughly described in this summary

Full-wave analysis and applications of EBG waveguides periodically loaded with metal ridges

In this paper, a fast and accurate full-wave analysis tool of passive structures based on Electromagnetic-Bandgap (EBG) waveguides periodically loaded with metal ridges is proposed. For this purpose, a very efficient Integral Equation (IE) technique is followed to model the planar steps involving arbitrary waveguides. The well-known Boundary Integral - Resonant Mode Expansion (BI-RME) method is used to obtain the modal chart of the ridged waveguides. In order to show the advantages of this tool, a periodically loaded E-plane filter with improved stopband performance is analyzed and compared to standard implementation. Dispersion relations are also derived and used as guidelines for designing an EBG fifth-order low-pass filter

Low-cost Implementation of a Waveguide-based Microwave Filter in Substrate Integrated Waveguide (SIW) Technology

This paper presents the design and practical implementation of a waveguide-based microwave filter in Substrate Integrated Waveguide (SIW) technology. The use of SIW technology for implementing waveguide filters makes the presented design specially aimed for being used in undergraduate courses related to microwave engineering and filter designing. Their low cost and easiness from the filter fabrication point of view allows their use in microwave laboratory courses where students can implement their own theoretical filter designs and measure their frequency response. The requiring mechanics in the manufacturing of microwave filters in waveguide technology (both rectangular and circular) makes its use practically unfeasible in academic laboratories because of its cost. For this reason, a practical design example of a waveguide iris filter using the impedance inverter model is proposed in this paper for academic laboratories, using SIW technology. This is a low cost and easy to manufacture technology. The overall process includes the design of the ideal band-pass prototype filter using the impedance inverter and its implementation in an inductive iris-coupled waveguide filter, by using a developed electromagnetic simulator based on the mode-matching technique. Finally, the equivalent filter in SIW technology is obtained and optimized by using HFSS simulator, including a SIW to microstrip transition. A prototype of the designed filter has been fabricated and measured, showing a good agreement between measurements and simulations.Ministerio de Economía y Competitividad, TEC2013-47037-C5-4-R

A novel band-pass filter based on a periodically drilled SIW structure

The design and fabrication of a band-pass step impedance filter based on high and low dielectric constant sections has been realized on substrate integrated waveguide (SIW) technology. The overall process includes the design of the ideal band-pass prototype filter, where the implementation of the impedance inverters has been carried out by means of waveguide sections of lower permittivity. This can be practically achieved by implementing arrays of air holes along the waveguide. Several SIW structures with and without arrays of air holes have been simulated and fabricated in order to experimentally evaluate their relative permittivity. Additionally, the equivalent filter in SIW technology has been designed and optimized. Finally, a prototype of the designed filter has been fabricated and measured, showing a good agreement between measurements and simulations, which demonstrates the validity of the proposed design approach.This work was supported by the Ministerio de Economía y Competitividad, Spanish Government, under the Research Project TEC2013-47037-C5-4-R

Método alternativo de medida de los parámetros de radiación de antenas empleando equipo de bajo coste

Los programas de la titulación Ingeniero de Telecomunicación incluyen en general un buen número de asignaturas relacionadas con el estudio de radiopropagación y antenas. Un bloque común a todas estas asignaturas suele ser la caracterización de los parámetros de radiación de antenas. El problema a encarar en estos casos (sobre todo por parte de titulaciones de implantación reciente en universidades españolas) es el elevado coste que requiere la instrumentación de medida (cámara anecoica, sistema de posicionamiento, software para pasar de campo cercano a campo lejano, analizador de redes vectorial). En este artículo se muestra una solución a adoptar para incluir en las asignaturas de antenas sesiones prácticas de la medida del diagrama de radiación en plano-E y en plano-H de diversas antenas de UHF y SHF empleando para ello únicamente varias antenas, un rotor y un ordenador con una tarjeta sintonizadora de televisión cuyo software proporcione la medida del nivel de señal recibido por las antenas.Eje: Educación universitaria: Experiencias educativasRed de Universidades con Carreras en Informática (RedUNCI

Full-wave modal analysis of slow-wave periodic structures loaded with elliptical waveguides

In this paper, a novel full-wave method for the modal characterization of periodic structures loaded with elliptical waveguides is presented. This method relies on an integral equation formulation solved via the method of moments, which finally leads to the solution of a standard eigenvalue problem. The required modal spectrum of elliptical waveguides is determined through the boundary integral-resonant mode expansion technique. For validation purposes, the proposed analysis method is first successfully applied to periodic waveguide structures already considered in the technical literature. Then, our new algorithm is used to compute the related Brillouin diagrams and the interaction impedance of new periodic structures loaded with elliptical waveguides. Not only the main interacting mode (such as the TM 01 mode) is studied, but higher-order Floquet modes are also considered. These results have potential applications as slow-wave structures for high-power microwave devices and possibly filtering structures at millimeter-wave frequencies.This work was supported by the Ministerio de Educación y Ciencia, Spanish Government, under the coordinated Research Project TEC 2007/67630-C03-01

Efficient modal analysis of periodic structures loaded with arbitrarily shaped waveguides

In this paper, a novel full-wave method for the modal characterization of closed metallic periodic structures based on arbitrarily shaped waveguides is presented. This method relies on an integral equation formulation solved via the method of moments, which finally leads to the solution of a standard eigenvalue problem. The required modal spectrum of waveguides with arbitrary cross section is determined through the boundary integral-resonant mode expansion technique. For validation purposes, the proposed analysis method is first successfully applied to standard waveguide periodic geometries already considered in the technical literature. Our new algorithm is then used to identify the higher order Floquet modes, as well as to compute the related Brillouin diagrams, of complex closed metallic periodic structures loaded with arbitrarily shaped waveguides.This work was supported by the Ministerio de Educación y Ciencia, Spanish Government, under coordinated Research Project TEC 2007/67630-C03-01

Fast and accurate CAD tool of periodically loaded E-plane filters

In this paper, a fast and accurate Computer-Aided Design (CAD) tool of periodically loaded E-plane filters is proposed. The tool is based on a very efficient Integral Equation (IE) technique that provides a full-wave modal analysis of discontinuities between arbitrarily shaped waveguides, i.e. ridge waveguides, and rectangular ones. For solving the complete filter, the Boundary Integral - Resonant Mode Expansion (BI-RME) method is also employed. In order to show the advantages of this CAD tool, a periodically loaded E-plane filter with improved stop-band performance is analyzed and compared to standard solutions. For validation purposes, numerical and experimental results are successfully compared

Study of Periodic Dielectric Frequency-selective Surfaces under 3D Plane Wave Incidence

A periodic Dielectric Frequency-Selective Surface (DFSS) is studied under 3D plane-wave incidence, whose unit cell in the periodic direction is composed of a dielectric grating and a homogeneous dielectric layer. The structure is excited by a linearly polarized plane-wave. The procedure for computing the Brillouin diagram of the structure under 2D plane-wave incidence with TE or TM polarization was already described by the authors, and the extension to the 3D incidence case has been performed in a similar way. Following the same formalism, it has been obtained the Generalized Scattering Matrix (GSM) of one period of the infinite periodic lattice. This requires the knowledge of the modal spectrum in both homogeneous and periodic dielectric media. To this end, a numerical technique based on a vectorial modal method originally proposed by the authors has been used. Once the S matrix of one period of the periodic medium is computed, the corresponding generalized ABCD matrix of the unit cell can be easily derived, which provides a standard multimodal eigenvalue matrix problem whose solution yields the transverse field distributions and the modal propagation constants in the periodic lattice. In the 3D incidence case, a given number of modes considered in the construction of the ABCD matrix yields the dispersion diagram of TE and TM modes simultaneously. The identification of the modes can be easily performed through the comparison of their dispersion diagram with the reflectance spectra of the structure under a given incidence polarization (TE or TM). Finally, some numerical result effects, varying the incidence direction of the exciting plane-wave in the dispersion diagram of an Electromagnetic Band Gap (EBG) material, are shown.This work was supported by the Ministerio de Economía y Competitividad, Spanish Government, under the coordinated projects TEC2013-47037-C5-4-R and TEC2013-47037-C5-1-R