Novel design procedure for microwave filters

In this paper a novel design procedure is described for the hardware implementation of microwave filters. The procedure is based on a very accurate and efficient software package for the full-wave simulation of the structure and consists of a step-by-step procedure that systematically leads to dimensioning of the mplete filter geometry. Following the procedure described, each successive step only involves the dimensioning of a maximum of four physical parameters. As an illustrative example, the design of a nine pole non-uniform filter is discussed indicating how the procedure is indeed very efficient

Multimode network representation of two dimensional steps in rectangular waveguides

In this paper a new Multimode Network representation for arbitrary rectangular waveguide junctions is presented. The energy coupling between the higher order modes excited in the junction is rigorously described via a multimode impedance matrix representation that can be used to build very efficient and accurate software tools for the analysis of complex structures. The elements of the impedance matrix are obtained from the solution of an integral equation. The main feature of the approach is that the kernel of the integral equation derived is essentially independent from frequency and therefore, the most time consuming task, namely the solution of the integral equation, need to be performed only once per each geometry. The formulation of the method is discussed and the form of the integral equation is given, showing explicitly the dependence with the frequency. A frequency extraction procedure that can lead to a considerable time saving for the analysis of complex structures is also discussed. Finally the design of a commercial communication satellite filter structure is presented, including comparisons between our analysis and measurements of the manufactured hardware

Novel Leaky Wave Antennas for Mobile Communication Systems, Satellite and Radar Applications

[ESP] Se propone una tecnología nueva híbrida guiada-impresa para el desarrollo de antenas leaky wave compactas para aplicaciones de comunicaciones móviles, aplicaciones por satélite y sistemas radar. El dispositivo consiste en una guía base que incorpora un circuito impreso de bajo coste, y que es capaz de excitar una onda leaky wave utilizando el llamado mecanismo de radiación por asimetría.Además es posible sintetizar diagramas de radiación anchos o estrechos, según lo requiera la aplicación a la que se va a destinar la antena. También es posible controlar y ajustar, con la nueva tecnología, el nivel de lóbulos secundarios usando un novedoso sistema de tapering también desarrollado. De esta forma de pueden reducir los niveles de interferencias a los valores adecuados. Otra ventaja es que se puede ajustar a voluntad el ángulo de apuntamiento de la antena, permitiendo su aplicación en una gran cantidad de sistemas diferentes. Por otro lado, las características del campo eléctrico del modo excitado resulta en una onda radiada con polarización lineal horizontal, y con una componente de polarización cruzada muy baja. Por tanto la tecnología es ideal en aplicaciones donde la polarización lineal es empleada, con unos requerimientos de pureza de polarización muy altos.Otra particularidad que puede ser interesante para ciertas aplicaciones de seguimiento de satélites o Radar, es la propiedad de escaneado de haz en frecuencia, inherente en las antenas leaky wave. La característica más innovadora de la tecnología propuesta es que todas estas características de radiación pueden controlarse fácilmente y se forma muy barata utilizando un circuito impreso sencillo. Con esta idea, diferentes niveles de lóbulos secundarios, direcciones de apuntamiento, y anchos de haz pueden sintetizarse cambiando simplemente el circuito impreso que se incorpora a la estructura de la antena, aumentando por tanto la flexibilidad de diseño. Finalmente, se ha desarrollado un procedimiento eficiente para el diseño y optimización de antenas utilizando la nueva tecnología. La técnica permite sintetizar diagramas de radiación en un tiempo muy corto, y es de esperar que reduzca mucho el tiempo y coste asociado al diseño y producción de este tipo de elementos, para su incorporación en sistemas de comunicaciones móviles, aplicaciones por satélite y sistemas radar.[ENG] A hybrid waveguide-printed technology is proposed for the development of compact leaky wave antennas for Mobile Communication Systems, Satellite and Radar applications. A compact waveguide is used to host a low cost printed circuit, which launches a leaky wave mode using the asymmetry radiation mechanism. In Fig.1 above we show the basic structure of the new leaky wave proposed. The radiation properties and behavior of the structure are fully controlled with the simple printed circuit design placed in the structure. Therefore, by using inexpensive photolithographic manufacturing processes different radiation characteristics can be synthesized. The new antennas can operate as part of wideband communication systems, due to the travelling wave nature of the leaky mode radiation operation, which provides broadband input matching. The wide matching capabilities of the new technology are illustrated in Fig.2 above, where –20dB of matching is demonstrated over a 17% fractional bandwidth. Both wide and narrow beamwidths can be implemented with the technology proposed, according to the needs of the particular application. Furthermore, sidelobes levels can be easily controlled and adjusted with a novel tapering mechanism developed within the technology, in order to reduce interferences. A particular pointing elevation angle can also be designed and adjusted as required. Due to the distribution of the electric field associated to the leaky mode employed for operation, the antenna is able to radiate with linear horizontal polarization, exhibiting very low levels of cross-polarization. It is therefore suitable for applications where linear, high purity polarization is required. All these interesting properties of the new technology are demonstrated in the radiation patterns shown in Fig.3. Frequency scanning capabilities are inherent to this technology, and can be exploited for target/satellite tracking and Radar applications. The unique feature of the technology proposed is that the radiation properties of the structure are controlled by a simple, easy manufacturing, low cost printed circuit placed on the host waveguide. Different sidelobe levels, pointing directions, and beamwidths can be implemented by designing different printed circuits, therefore increasing the flexibility of the technology. A simple and efficient design procedure has been developed for the optimization of the antennas to rapidly achieve targeted radiation characteristics. This is expected to reduce time and cost production associated to the development of high demanding radiation front-ends associated to next generation Mobile Communications Systems, Satellite and Radar Applications. The pointing angle and side lobes level control are illustrated in the radiation patterns shown in Fig.4 above.[ESP]La Universidad Politécnica de Cartagena, a través de su Grupo de Electromagnetismo aplicado a las Telecomunicaciones, ofrece una solución novedosa para emplear en sistemas de comunicaciones móviles, aplicaciones por satélite y sistemas Radar. La solución consiste en la mejora de los sistemas radiantes que estos sistemas incorporan en sus cabeceras de radiofrecuencia, y que se utilizan para asegurar la correcta cobertura y calidad de servicio. Se ofrecen antenas leaky wave compactas en una tecnología nueva llamada híbrida-impresa, que proporcionan flexibilidad de diseño, y reducen costes de producción al simplificar los métodos de fabricación. Se pretende buscar empresas interesadas en integrar esta nueva tecnología en los nuevos sistemas de comunicaciones móviles, aplicaciones por satélite y sistemas radar mediante acuerdos de licencia, contratos de investigación o asesoría técnica.[ENG]The Technical University of Cartagena (Electromagnetics and Telecommunications Research Laboratory) in Spain, offers a novel solution for Mobile Communication Systems, Satellite and Radar Applications. The novel solution is focused on the improvement of the radiation front-end that such systems incorporate to assure coverage and quality of service. Compact leaky wave antennas in hybrid printed multilayered technology are offered to provide design flexibility, easy manufacturing process and reduction in cost production. Properties such as frequency scanning capabilities are easily implemented with the proposed technology for target/satellite tracking and Radar applications. We are looking for companies who are interested in the integration of this new antenna technology with emerging Mobile Communications Systems, Satellite and new Radar Applications. This collaboration can be concretized through license agreements, research contracts or technical consultancy to assist with the new technology integration.[ESP]La nueva tecnología propuesta ofrece alta flexibilidad para el diseño de diagramas de radiación de alta complejidad, combinando un bajo coste y facilidad de fabricación. Las características radiantes del dispositivo propuesto se controlan fundamentalmente con baratos circuitos impresos, que pueden fabricarse con procesos sencillos de fotolitografía. La nueva tecnología es apropiada para sistemas de comunicaciones móviles, aplicaciones por satélite y sistemas radar, que requieran complejos diagramas de radiación para su operación y funcionamiento. Por otro lado se ha desarrollado un sistema de diseño muy efectivo que reduce el tiempo de diseño y producción de los equipos, reduciendo considerablemente los costes asociados para las empresas.[ENG]The new antenna technology offers high design flexibility of complex radiation patterns combined with easy manufacturing topology. The radiation characteristics are fully controlled using inexpensive, fast production printed circuits, which can be manufactured using simple, low-cost photolithographic processes. The new technology is appropriate for Mobile Communications Systems, Satellite and Radar Applications where complex radiation patterns must be used. In addition, a fast and effective design procedure is for reducing time design and overall production cost.Diseño de dispositivos de microondas para aplicaciones por satélite. Sistemas radiantes para aplicaciones por satélite

Multimode synthesis procedure for microwave filters based on thick inductive windows

For several types of microwave filters for space application it is important to manufacture hardware without tuning elements. For this to be possible, one needs a systematic procedure to codvert ideal elements, such as resonators and impedance inverters, into actual waveguide lengths and discontinuities. The situation is further complicated by the fact that waveguide discontinuities excite higher order modes that interacting with each other can have very strong effects. In this paper we first outline the theory behind a very efficient computer code for the simulation of microwave filters based on thick inductive windows. Then we describe in detail a step-by-step procedure that, based on the code developed, allows for the rapid design of this class of microwave filters without any tuning elements. Two actual examples of design are also discussed and comparisons presented between measurements and simulations

Multimode Network Analysis of Planar Transmission Lines

An alternative approach for the full wave analysis of single or coupled planar transmission lines is presented. Following the proposed approach, a multiple (or single) transmission line structure is viewed as series of staked (or single) transverse discontinuities in a parallel plate waveguide. As a consequence, both top and side coupled structures can be studied. Each individual discontinuity is described in terms of a multimode equivalent network representation. The complete cross section of the planar transmission line structure is then described in terms of a transverse equivalent network and a simple transverse resonance technique is then used to obtain the dispersion behavior, the modal field of the structure, and the characteristic impedances. The multimode equivalent network representations of the individual discontinuities used in this paper have been derived else where and are given in terms of impedance or admittance matrices that are essentially independent from frequency. As a result, they need to be computed only once for each given geometry thus leading to codes that are computationally very efficient.European Space Agenc

Rigorous, Multimode Equivalent Network Representation of Capacitive Discontinuities

In this paper we present novel, rigorous, multimode equivalent network representations for a variety of zero-thickness capacitive windows and obstacles in a parallel plate waveguide. A key feature of these representations is that the coupling between all of the modes excited is described by a matrix whose elements do not depend on frequency or absolute dimensions. The value of the results presented is that the networks developed can be used to analyze rigorously a large variety of single and coupled planar transmission line structures.European Space Agenc

Process for compensating local magnetic perturbations on ferromagnetic surfaces

This paper addresses a practical application for the compensation of a local magnetic perturbation in a ship in the near field region. The process will avoid expensive deperming techniques usually applied to ships to treat magnetic anoma- lies. The technique includes a new system to construct magnetic maps on flat ferromagnetic surfaces. Once the mag- netic maps are obtained, a new system is proposed to evaluate and locate local magnetic perturbations. Once the local perturbations are located, they are compensated by local degaussing coils. The new technique has been applied to the detection of local magnetic perturbations in four naval platforms. Two of them presented important magnetic anomalies, and were successfully detected and corrected by applying the new technique, thus showing its practical value

Diseño e implementación de una aplicación multiplataforma para la presentación y seguimiento de programas médicos

[ES] El presente proyecto expone el análisis, diseño e implementación de una solución software para centros médicos. Esta otorga a los centros los medios para mejorar la comunicación y realizar el seguimiento del progreso de sus pacientes. Los pacientes hacen uso de este software para proporcionar la información de seguimiento de un programa del centro al que están suscritos y para visualizarlo. Se lleva a cabo en colaboración con la empresa de desarrollo de software BiiT Sourcing Solutions mediante la implementación de una aplicación multiplataforma. Esta cuenta con una serie de servicios y sistemas asociados también explicados en esta memoria.[CA] El present projecte exposa l’anàlisi, el disseny i la implementació d’una solució software per a centres mèdics. Aquesta atorga als centres els medis per a millorar la comunicació i realitzar el seguiment del progrés dels seus pacients. Els pacients fan ús d’aquest software per a proporcionar la informació de seguiment d’un programa del centre al qual estan subscrits i per a visualitzar-lo. Es du a terme en col·laboració amb l’empresa de desenvolupament de software BiiT Sourcing solutions mitjançant la implementació d’una aplicació multiplataforma. Aquesta compta amb una sèrie de servicis i sistemes associats també explicats en aquesta memòria.[EN] The present project presents the analysis, design and implementation of a software solution for medical centres. It provides the centres the means to improve the communication and carry out the monitoring of their patients progress. The patients make use of this software to provide their tracking information of a program from the centre which they are subscribed to. Also, for visualizing this information. It is carried out in collaboration with the software development company BiiT Sourcing Solutions by the implementation of a multi platform application. The application also has a series of associated systems and services which are explained in this memory.Melcon Alvarez, A. (2017). Diseño e implementación de una aplicación multiplataforma para la presentación y seguimiento de programas médicos. http://hdl.handle.net/10251/88422.TFG

The Summation by Parts Algorithm: A New Efficient Technique for the Rapid Calculation of Certain Series Arising in Shielded Planar Structures

This paper presents a new technique for the convergence acceleration of a large class of series often arising in electromagnetic problems. The technique is based on the recursive application of the integration-by-parts technique to discrete sequences, thus the given name of the "summation-by-parts" technique. It is shown that the new technique greatly enhances the convergence rate of the series treated, and very small relative errors are obtained by performing a few simple operations. The new technique is applied to the efficient numerical calculation of the Green's functions in a parallel-plate waveguide.Universidad Politécnica Federal de Lausanne (EPFL

Green's functions in layered media: Imaginary axis integration and asymptotic behavior

This paper presents an efficient technique for evaluating Green’s functions associated to layered media, when cast in the space domain as Sommerfeld integrals. The theoretical developments needed to set up the numerical algorithm throw a new light on the asymptotic behavior of these Green’s functions for large transverse source-observer distances.The authors wish to thank Rich Hall from Boulder Microwave Technologies Inc.and Yan Brand from Ecole Polytechnique Fkdkrale de Lausanne for helpful discussion and advice