Limit for the proportion of remaining samples in the modestirred chamber sample selection technique

An expression is derived for the maximum proportion of remaining samples in the sample selection technique for mode-stirred chamber measurements. The limit is independent of the selection algorithm used. The limit is verified in simulations as well as measurement examples.This work was supported in part by the Spanish National R&D Programme through TEC2008-05811, and by Fundacio´n Se´neca, the R&D coordinating agency for the Region of Murcia (Spain) under the 11783/PI/09 and 11610/IV2/09 project

Antena impresa de banda dual

Número de publicación: 2 156 832 Número de solicitud: 009902216Cuenta con una placa de substrato dieléctrico (1) cuya cara anterior presenta un parche radiante (2) alimentado por un tramo de linea microtira (3) y cuya cara posterior presenta un plano de masa (4). Este parche (2) tiene forma de triángulo isósceles, conectando uno de sus vértices con el referido tramo (3), mientras que paralelamente al lado opuesto a dicho vértice hay una ranura (5) en el parche (2) que actúa como filtro posibilitando una operación dual cuyas dos frecuencias de resonancia se controlan mediante la variación del tamaño del parche (2) y de la longitud de la ranura (5). Dichas frecuencias se pueden ajustar a los valores de 900 y 1800 MHz, posibilitando así la aplicación de la antena en telefonóa móvil dual con sistemas GSM y DCS-1800.Universidad Politécnica de CartagenaUniversidad Politécnica de Valenci

Precise dielectric properties determination of laminar shaped materials in a partially filled waveguide

An enhanced technique for complex dielectric properties characterization of laminar-shaped materials is presented. The technique is based upon scattering measurements of a partially-filled rectangular waveguide. The influence of the different parameters regarding the achievable accuracy have also been analyzed in order to determine the optimum sample configuration. Measurements of some commercial dielectric substrates used for printed antenna design were performed and have been used for validation purpose

Efficient location strategy for airport surveillance using mode-s multilateration systems

© Cambridge University Press and the European Microwave Association, 2012[EN] In this paper, the use of regularization methods to solve the location problem in multilateration systems, using Mode-S signals, is studied, evaluated, and developed. The Tikhonov method has been implemented as a first application to solve the classical system of hyperbolic equations in multilateration systems. Some simulations are obtained and the results are compared with those obtained by the well-established Taylor linearization and with the Cramér-Rao lower bound analysis. Significant improvements, for the accuracy, convergence, and the probability of location, are found for the application of the Tikhonov method. © Cambridge University Press and the European Microwave Association, 2012.Mr. Ivan A. Mantilla-Gaviria has been supported by a FPU scholarship (AP2008-03300) from the Spanish Ministry of Education. Moreover, the authors are grateful to Thales Italia S. p. A. (Dr. Ing. R. Scaroni) who supplied the geometry of the Multilateration system in Linate (Milan, Italy) airport.Mantilla Gaviria, IA.; Leonardi, M.; Galati, G.; Balbastre Tejedor, JV.; Reyes Davó, EDL. (2012). Efficient location strategy for airport surveillance using mode-s multilateration systems. International Journal of Microwave and Wireless Technologies. 1-8. https://doi.org/10.1017/S1759078712000104S18Bertero, M., Boccacci, P., Brakenhoff, G. J., Malfanti, F., & Voort, H. T. M. (1990). Three-dimensional image restoration and super-resolution in fluorescence confocal microscopy. Journal of Microscopy, 157(1), 3-20. doi:10.1111/j.1365-2818.1990.tb02942.xSchau, H., & Robinson, A. (1987). Passive source localization employing intersecting spherical surfaces from time-of-arrival differences. IEEE Transactions on Acoustics, Speech, and Signal Processing, 35(8), 1223-1225. doi:10.1109/tassp.1987.1165266Gfrerer, H. (1987). An a posteriori parameter choice for ordinary and iterated Tikhonov regularization of ill-posed problems leading to optimal convergence rates. Mathematics of Computation, 49(180), 507. doi:10.1090/s0025-5718-1987-0906185-4[6] Galati G. ; Leonardi M. ; Tosti M. : Multilateration (local and wide area) as a distributed sensor system: lower bounds of accuracy, in European Radar Conf., EuRAD, Amsterdam, 30–31 October 2008.[1]The European Organisation for the Safety of Air Navigation. The ATM surveillance strategy for ECAC, in European Air Traffic Management Programme, Eurocontrol, 2008.Torrieri, D. (1984). Statistical Theory of Passive Location Systems. IEEE Transactions on Aerospace and Electronic Systems, AES-20(2), 183-198. doi:10.1109/taes.1984.310439[12] Perl E. ; Gerry M.J. : Target localization using TDOA distributed antenna, US 2005/0035897 A1, USA, 17 February 2005.[2]The European Organisation for Civil Aviation Equipment. Ed-117, mops for mode s multilateration systems for use in advanced surface movement guidance and control systems (a-smgcs), in EUROCAE (Ed.), EUROCAE, November 2003.Leonardi, M., Mathias, A., & Galati, G. (2009). Two efficient localization algorithms for multilateration. International Journal of Microwave and Wireless Technologies, 1(3), 223-229. doi:10.1017/s1759078709000245Ho, K. C., & Chan, Y. T. (1993). Solution and performance analysis of geolocation by TDOA. IEEE Transactions on Aerospace and Electronic Systems, 29(4), 1311-1322. doi:10.1109/7.259534FOY, W. (1976). Position-Location Solutions by Taylor-Series Estimation. IEEE Transactions on Aerospace and Electronic Systems, AES-12(2), 187-194. doi:10.1109/taes.1976.308294Phillips, D. L. (1962). A Technique for the Numerical Solution of Certain Integral Equations of the First Kind. Journal of the ACM, 9(1), 84-97. doi:10.1145/321105.321114Hanke, M., & Raus, T. (1996). A General Heuristic for Choosing the Regularization Parameter in Ill-Posed Problems. SIAM Journal on Scientific Computing, 17(4), 956-972. doi:10.1137/0917062Golub, G. H., Heath, M., & Wahba, G. (1979). Generalized Cross-Validation as a Method for Choosing a Good Ridge Parameter. Technometrics, 21(2), 215-223. doi:10.1080/00401706.1979.10489751Harrington, R. F. (1993). Field Computation by Moment Methods. doi:10.1109/978047054463

Líneas de investigación en técnicas de alta frecuencia

Se presentan las realizaciones en investigación y desarrollo de los Grupos de Cátedra de Microondas, Antenas y Propagación de Ondas, Radiolocalización, y se describen las líneas futuras de investigación que desarrollarán en los próximos tres años

Célula calefactora, calefactor que hace uso de la misma, sistema de calefacción y uso del mismo

[EN] The present invention details a solution to the problem of transforming, with high efficiency, microwave energy into heat by means of heating units in the form of low-power heating cells that allow microwave energy to be propagated along transverse electromagnetic mode electrical transmission lines to ceramic materials with high dielectric loss in the microwave region. Said low-power heating cells are integrated in a heating unit. The set of heating units form a heating system with microwave energy that uses an electric low-power line.[ES] La presente invención detalla una solución al problema de transferir con alta eficiencia la energía microondas en calor mediante unidades calefactoras en forma de células calefactoras de baja potencia que permiten propagar la energía de microondas mediante líneas de transmisión eléctrica de modos transversales electromagnéticos a materiales cerámicos con altas pérdidas dieléctricas en la región de microondas. Dichas células calefactoras de baja potencia se integran en un calefactor unitario. El conjunto de calefactores unitarios conforman un sistema de calefacción con energía microondas que emplea una línea de baja potencia eléctrica.Peer reviewedConsejo Superior de Investigaciones Científicas (España), Universitat Politécnica de Valencia, VilamarxantA1 Solicitud de patente con informe sobre el estado de la técnic

Heating cell, heater using same, heating system and use thereof

La presente invención detalla una solución al problema de transferir con alta eficiencia la energía microondas en calor mediante unidades calefactoras en forma de células calefactoras de baja potencia que permiten propagar la energía de microondas mediante líneas de transmisión eléctrica de modos transversales electromagnéticos a materiales cerámicos con altas pérdidas dieléctricas en la región de microondas. Dichas células calefactoras de baja potencia se integran en un calefactor unitario. El conjunto de calefactores unitarios conforman un sistema de calefacción con energía microondas que emplea una línea de baja potencia eléctrica.Peer reviewedConsejo Superior de Investigaciones Científicas (España), Universidad Politécnica de Valencia, Microbiotech S.L.A1 Solicitud de patente con informe sobre el estado de la técnic

Célula calefactora, calefactor que hace uso de la misma, sistema de calefacción y uso del mismo

[EN] The present invention details a solution to the problem of transforming, with high efficiency, microwave energy into heat by means of heating units in the form of low-power heating cells that allow microwave energy to be propagated along transverse electromagnetic mode transmission lines to ceramic materials having high dielectric loss in the microwave region. Said low-power heating cells are integrated into a unit heater. A group of unit heaters forms a microwave-energy heating system that uses a low-electric-power line.[ES] Célula calefactora, calefactor que hace uso de la misma, sistema de calefacción y uso del mismo. La presente invención detalla una solución al problema de transferir con alta eficiencia la energía microondas en calor mediante unidades calefactoras en forma de células calefactoras de baja potencia que permiten propagar la energía de microondas mediante líneas de transmisión eléctrica de modos transversales electromagnéticos a materiales cerámicos con altas pérdidas dieléctricas en la región de microondas. Dichas células calefactoras de baja potencia se integran en un calefactor unitario. El conjunto de calefactores unitarios conforman un sistema de calefacción con energía microondas que emplea una línea de baja potencia eléctrica.Peer reviewedConsejo Superior de Investigaciones Científicas (España), Universidad Politécnica de Valencia, Microbiotech S.L.A1 Solicitud de patente con informe sobre el estado de la técnic

Heat flux and heat generation characterisation in a wet-laminar body in microwave-assisted drying: an application to microwave drying of leather

Heat fluxes through a laminar body have been modelled from a parabolic temperature distribution assumption when the material is irradiated with microwaves and immersed in a convective air flow. The heat equation has been analysed and a relationship between thermal conductivity, temperatures and net heat flux through the material surface has been established. This study has been successfully applied to leather hides when they are dried in a combined microwave-hot air oven. With regard to the development of this work, dielectric and temperature measurements have been demonstrated to be of the utmost importance.The authors wish to thank Incusa S.A., for the provision of leather samples, IMPIVA for the financial support in the development of the study and Electrothermie Microonde of the ENSEEIHT in Toulose for the construction of the microwave prototype

A Novel Technique for Deembeding the Unloaded Resonance Frequency from Measurements of Microwave Cavities

[EN] A novel technique to extract the influence of coupling networks on the resonant frequency of cavities in one-port measurements is presented. The determination of the unloaded resonant frequency is performed directly from measurements without either the need to obtain the electromagnetic fields in the resonator or to deembed the delay of transmission lines from the measuring equipment to the resonator. The importance of the Foster's form on the modeling of the frequency detuning of the resonators is also discussed and a criterion for the choice of the appropriate Foster's form is suggested. The procedure is validated with simulations and experimental measurements of manufactured cavitiesCanós Marín, AJ.; Catalá Civera, JM.; Penaranda-Foix, FL.; Reyes Davó, EDL. (2006). A Novel Technique for Deembeding the Unloaded Resonance Frequency from Measurements of Microwave Cavities. IEEE Transactions on Microwave Theory and Techniques. 54(8):3407-3416. https://doi.org/10.1109/TMTT.2006.8778333407341654