Design of planar wideband bandpass filters from specifications using a two-step aggressive space mapping (ASM) optimization algorithm

This paper is focused on the automated and unattended optimization of a type of planar wideband bandpass filters by means of aggressive space mapping (ASM). The considered filters are microstrip filters implemented through a combination of shunt connected stepped impedance resonators (SIRs) and grounded stubs coupled through admittance inverters. The most relevant and novel aspect of this paper is the fact that the filter layout is automatically generated from filter specifications, i.e., central frequency, fractional bandwidth, in-band ripple and order, without the need of any external aid to the design process. To achieve this layout generation, filter optimization has been divided into two independent ASM processes. The first one generates the filter schematic (circuit element values) providing the required specifications. This first iterative process is necessary since, due to the narrow band operation of the admittance inverters, the target specifications are achieved by compensating the effects of such narrow band operation. The purpose of the second ASM algorithm is to automatically generate the layout from the filter schematic resulting from the first ASM process. To validate the new two-step ASM optimization tool, two sets of filter specifications (inputs of the developed tool), are considered. The generated filter layouts exhibit frequency responses that satisfy the specifications, and are in excellent agreement with the responses of the schematics.This work was supported by MINECO-Spain (projects TEC2010-17512 METATRANSFER, TEC2010-21520-C04-01 and TEC2013-47037-C5-1-R, CONSOLIDER EMET CSD2008-00066, TEC2013-40600-R and TEC2013-49221-EXP), Generalitat de Catalunya (project 2014SGR-157), and Institucio Catalana de Recerca i Estudis Avancats (who has awarded F. Martin). This paper was presented in part at the IEEE MTT-S International Microwave Symposium, Tampa Bay, FL, USA, June 1-6, 2014.Sans, M.; Selga, J.; Rodríguez Pérez, AM.; Bonache, J.; Boria Esbert, VE.; Martín, F. (2014). Design of planar wideband bandpass filters from specifications using a two-step aggressive space mapping (ASM) optimization algorithm. IEEE Transactions on Microwave Theory and Techniques. 62(12):3341-3350. https://doi.org/10.1109/TMTT.2014.236547733413350621

Un congrès scientifique à l’école secondaire: articulant l’apprentissage basé en projets et l’enquête scientifique

Los Proyectos de Investigación son una aproximación didáctica que recoge elementos del Aprendizaje Basado en Proyectos y la Enseñanza de las Ciencias Basada en la Indagación. Se describe el diseño y aplicación de un “Proyecto de Investigación” con alumnado de 1º de ESO del Instituto de Educación Secundaria Marta Estrada (Granollers) sobre los Ciclos Biogeoquímicos, la Hidrosfera y la Atmósfera. En éste el alumnado organiza y participa como investigador en un Congreso Científico Escolar sobre Contaminación. A partir de los resultados obtenidos en la aplicación, se identifican elementos de importancia en el diseño de Proyectos de Investigación, relativos a la autonomía del alumnado, el papel del contexto y el desarrollo de las dimensiones conceptual, procedimental y epistémica de la Competencia Científica.Inquiry Projects are a didactic approach including elements from Project-Based Learning and Inquiry-Based Science Education. We describe the design and application of a “Research Project” with 12-years-old students on Biogeochemical Cycles, Hydrosphere and Atmosphere. In this project, students organize a Scientific Congress on Pollution and participate in it as researchers. From the results of the application, we identify key elements in developing Inquiry Projects, related to the students’ self-regulation, the role of the activity context and the development of the conceptual, procedural and epistemic dimensions of the Scientific Competence.Les Projets d'Enquête sont une stratégie didactique qui contient des éléments de l’Apprentissage Basé en Projets et de l’Enseignement des Sciences Fondé sur l'Investigation. Nous décrivons le dessin et application d’un «Projet de Recherche» avec des élèves de 12 ans sur les Cycles Biogéochimiques, l’Hydrosphère et l’Atmosphère. Les étudiants organisent un Congrès Scientifique sur la Pollution et y participent comme des chercheurs. D'après les résultats de l'application, nous identifions des éléments clé dans le dessin de Projets d'Enquête, associés à l'autonomie des étudiants, le rôle du contexte et le déroulement des dimensions conceptuelle, procédurale et épistémique de la Compétence Scientifique.Ministerio de Economía y Competitividad EDU2015-66643-C2-1-

Synthesis of split-rings-based artificial transmission lines through a new two-step, fast converging, and robust aggressive space mapping (ASM) algorithm

© 2013 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper is focused on the synthesis of artificial transmission lines based on complementary split ring resonators (CSRRs). The considered structures are microstrip lines with CSRRs etched in the ground plane and microstrip lines loaded with both CSRRs and series capacitive gaps. An aggressive space mapping (ASM) optimization algorithm, able to automatically generate the layout of these arti ficial lines, has been developed.The tool has been optimized in order to achieve fast convergence and to provide accurate results. The main relevant aspects of the proposed algorithm (based on a n ovel two-step ASM optimization approach) are: 1) the capability to provide the implementable circuit elements of the equivalent circuit model of the considered artificial lines and 2) the ability to converge in a few (unprecedented) iteration steps, due to a new procedure to generate the initial layouts (which are very close to the final ones). First, the software is tested through the synthesis of several CSRR-based microstrip lines, and then some practical application examples of such artificial lines are reported to illustrate the potential of the proposed synthesis tool.This work was supported in part by MICIIN-Spain under Project TEC2010-17512 METATRANSFER, Project TEC2010-21520-C04-01, Project CONSOLIDER EMET CSD2008-00066, and Grant AP2008-04707, Generalitat de Catalunya under Project 2009SGR-421, and MITyC-Spain under Project TSI-020100-2010-169 METASINTESIS.Selga, J.; Rodríguez Pérez, AM.; Boria Esbert, VE.; Martín, F. (2013). Synthesis of split-rings-based artificial transmission lines through a new two-step, fast converging, and robust aggressive space mapping (ASM) algorithm. IEEE Transactions on Microwave Theory and Techniques. 61(6):2295-2308. https://doi.org/10.1109/TMTT.2013.2259254S2295230861

Miniaturised and harmonic-suppressed rat-race couplers based on slow-wave transmission lines

Altres ajuts: JANDALUCIA/P12-TIC-1435In this study, a compact rat-race hybrid coupler with harmonic suppression based on slow-wave transmission lines (SW-TLs) is presented. Such artificial lines are implemented by periodic loading a host microstrip line with series meandered inductors and shunt patch capacitors. The presence of both loading elements has a twofold effect, i.e. phase velocity reduction (due to the enhancement of the effective inductance and capacitance of the periodic line), and the generation of a controllable stopband in the frequency response (due to the Bragg effect, inherent to periodicity). It is shown that by designing the unit cell of the periodic line with an electrical length of 45°, at least the first five harmonic bands of the rat-race coupler are efficiently suppressed, keeping the band of interest unaltered. Moreover, 79% size reduction, as compared to the ordinary coupler, is achieved in the reported SW-TL-based prototyp

Automated design of balanced wideband bandpass filters based on mirrored stepped impedance resonators (SIRs) and interdigital capacitors

This paper presents small balanced bandpass filters exhibiting wide differential-mode pass bands and high common-mode suppression. The filters are implemented in microstrip technology and their topology consists of multisection mirrored stepped impedance resonators (SIRs) alternating with mirrored interdigital capacitors. The mirrored SIRs provide the required common-mode transmission zeros to achieve effective rejection of that mode in the region of interest, i.e. the differential-mode pass band. An automated design method for such filters, based on aggressive space mapping, is reported. The method uses the equivalent circuit model of both the mirrored SIRs and the interdigital capacitors, and filter synthesis is based on a quasi-Newton iterative algorithm where parameter extraction is the key aspect. The automated design approach is illustrated through an order-3 filter, where it is demonstrated that the filter topology is generated from the specifications. As compared with previous balanced filters based on mirrored SIRs coupled through admittance inverters, the proposed filters of this work are smaller and the design method is simplified, since bandwidth compensation due to the narrowband functionality of the inverters is avoided.This work was supported by MINECO-Spain (projects no. TEC2013-47037-C5-1-R, TEC2013-40600-R, and TEC2013-49221-EXP), Generalitat de Catalunya (project no. 2014SGR-157), and Institucio Catalana de Recerca i Estudis Avancats (who has awarded Ferran Martin).Sans, M.; Selga, J.; Vélez, P.; Rodriguez Perez, AM.; Bonache, J.; Boria Esbert, VE.; Martin, F. (2016). Automated design of balanced wideband bandpass filters based on mirrored stepped impedance resonators (SIRs) and interdigital capacitors. International Journal of Microwave and Wireless Technologies. 8(4-5):731-740. https://doi.org/10.1017/S1759078716000672S73174084-

Split rings-based differential transmission lines with common-mode suppression

A novel microstrip differential transmission line with common-mode noise suppression is proposed and experimentally validated. It is implemented by periodically etching complementary split ring resonators (CSRRs) in the ground plane. For the differential signals, the symmetry of the structure efficiently cancels the electric field components axial to the CSRRs, and these particles have no effect on signal transmission. However, the CSRRs are activated under common mode excitation, with the result of a stop-band behavior. For the designed and fabricated prototype device, over 20 dB suppression of common-mode noise is achieved over a frequency range from 1.18 GHz to 1.74 GHz.Ministerio de Ciencia e Innovació TEC2010-17512, CSD2008-00066Generalitat de Catalunya 2009SGR-42

Design of Capacitively Loaded Coupled-Line Bandpass Filters With Compact Size and Spurious Suppression

[EN] This paper is focused on the synthesis of capacitively loaded coupled lines for the design of bandpass filters with compact size and spurious suppression. The filters consist of cascaded pairs of coupled lines periodically loaded with patch capacitors. The loading capacitances provide a slow-wave effect to the coupled lines useful for filter miniaturization, whereas periodicity introduces bandgaps that can be controlled in order to achieve spurious suppression. Filter design is achieved following an automated process based on aggressive space mapping (ASM) optimization. The two reported examples, a third-order filter with central frequency f0=1.0 GHz, 8% fractional bandwidth, and 0.1-dB ripple level and a fifth-order filter with central frequency f0=1.8 GHz, 8% fractional bandwidth, and 0.1-dB ripple level, demonstrate the potential of the proposed ASM-based design approach, as well as the effectiveness of the loading capacitances to reduce filter size and reject the spurious bands. Significant size reduction in both filters is achieved, whereas the out-of-band rejection is better than 30 and 45 dB in the third-order and fifth-order filters, respectively, up to at least 4f0 .This work was supported in part by MINECO-Spain under Project TEC2013-47037-C5-1-R, Project TEC2013-40600-R, and Project TEC2013-49221-EXP, in part by the Generalitat de Catalunya under Project 2014SGR-157, and in part by FEDER funds. The work of F. Martin was supported by the Institucio Catalana de Recerca i Estudis Avancats. The work of M. Orellana was supported in part by the Universidad de Costa Rica, in part by MICITT, and in part by CONICITOrellana, M.; Selga, J.; Vélez, P.; Sans, M.; Rodríguez Pérez, AM.; Bonache, J.; Boria Esbert, VE.... (2017). Design of Capacitively Loaded Coupled-Line Bandpass Filters With Compact Size and Spurious Suppression. IEEE Transactions on Microwave Theory and Techniques. 65(4):1235-1248. https://doi.org/10.1109/TMTT.2016.2638843S1235124865

Automated Design of Common-Mode Suppressed Balanced Wideband Bandpass Filters by Means of Aggressive Space Mapping

The automated and unattended design of balanced microstrip wideband bandpass filters by means of aggressive space mapping (ASM) optimization is reported in this paper. The proposed filters are based on multisection mirrored stepped impedance resonators (SIRs) coupled through quarter-wavelength transmission lines, acting as admittance inverters.This work was supported by MINECO-Spain (projects TEC2013-47037-C5-1-R, TEC2013-40600-R, TEC2013-49221-EXP), Generalitat de Catalunya (project 2014SGR-157), Institucio Catalana de Recerca i Estudis Avancats (who awarded Ferran Martin), and by FEDER funds.Sans, M.; Selga, J.; Velez, P.; Rodriguez Perez, AM.; Bonache Albacete, J.; Boria Esbert, VE.; Martin, F. (2015). Automated Design of Common-Mode Suppressed Balanced Wideband Bandpass Filters by Means of Aggressive Space Mapping. IEEE Transactions on Microwave Theory and Techniques. 63(12):3896-3908. https://doi.org/10.1109/TMTT.2015.2495180S38963908631

Compact Wideband Balanced Bandpass Filters With Very Broad Common-Mode and Differential-Mode Stopbands

[EN] Compact balanced bandpass filters based on a combination of multisection mirrored stepped-impedance resonators and interdigital capacitors are presented in this paper. The considered filter topology is useful to achieve wide bandwidths for the differential mode, with broad stop bands for that mode, as well as very efficient common-mode suppression. By conveniently adjusting the transmission zeros for both operation modes, the differential- and common-mode stopbands can be extended up to significantly high frequencies. Filter size and this differential- and common-mode stopband performance are the main relevant characteristics of the proposed balanced filters. The potential of the approach is illustrated by the design of a prototype order-5 balanced bandpass filter, with central frequency $f_{0} = 1.8$ GHz, 48% fractional bandwidth (corresponding to 55.4% ¿3-dB bandwidth), and 0.04-dB ripple level. The filter is automatically synthesized by means of an aggressive space-mapping software tool, specifically developed, and two (pre- and post-) optimization algorithms, necessary to determine the transmission-zero frequencies. The designed filter is as small as $0.48lambda _{g} times 0.51lambda _{g}$ , where $lambda _{g}$ is the guided wavelength at the central filter frequency, and the differential-mode stopband extends up to at least 6.5 GHz with more than 22-dB rejection. The common-mode suppression is better than 28 dB from dc up to at least 6.5 GHz.This work was supported in part by MINECO-Spain under Project TEC2013-40600-R, Project TEC2016-75650-R, and Project TEC2016-75934-C4-1-R, in part by the Generalitat de Catalunya under Project 2014SGR-157, in part by the Institucio Catalana de Recerca i Estudis Avancats (who awarded F. Martin), and in part by by FEDER funds.Sans, M.; Selga, J.; Vélez, P.; Bonache, J.; Rodríguez Pérez, AM.; Boria Esbert, VE.; Martin Antonlin, F. (2018). Compact Wideband Balanced Bandpass Filters With Very Broad Common-Mode and Differential-Mode Stopbands. IEEE Transactions on Microwave Theory and Techniques. 66(2):737-750. https://doi.org/10.1109/TMTT.2017.2785246S73775066