Highly Versatile Coplanar Waveguide Line With Electronically Reconfigurable Bandwidth and Propagation Characteristics

[EN] This paper describes a coplanar waveguide coupled to two split-ring resonators that, in turn, are loaded with two different reactive elements. By these means, balanced composite right/left-handed-like (CRLH-like) and also dual balanced CRLH-like (D-CRLH-like) responses can be obtained with the same structure showing opposite propagation characteristics. This behavior is achieved by simply varying one of the reactive elements, i.e., the capacitive or inductive load. The physical behavior of these transmission lines has been successfully explained by means of a single equivalent circuit. Besides, the proposed transmission lines have an extended bandwidth due to the balanced nature of the structure. The bandwidth of these lines can be electronically controlled using varactor diodes reverse-biased by an external dc voltage. Thus, a reconfigurable cell with CRLH-like and D-CRLH-like propagation has been designed and manufactured. The simulated and measured results show fractional bandwidths from 0% (no transmission) to 9.3% for simulations and from 0% (no transmission) to 8.7% for measurements. Undoubtedly, these new proposed transmission lines will be useful for designing reconfigurable devices that can be used in future communication systems such as radar, wireless applications, global positioning systems, or radio-frequency identification systems, among others.This work was supported by the Ministerio de Economia y Competitividad, Spanish Government, under Research Project TEC2013-47037-C05-3-R and Research Project TEC2013-47037-C05-1-R and by the Ministerio de Educacion, Cultura y Deporte under the Fellowship Program for Training University Professors.Martinez Cano, L.; Lucas Borja, A.; Boria Esbert, VE.; Belenguer, A. (2017). Highly Versatile Coplanar Waveguide Line With Electronically Reconfigurable Bandwidth and Propagation Characteristics. IEEE Transactions on Microwave Theory and Techniques. 65(1):128-135. https://doi.org/10.1109/TMTT.2016.2613526S12813565

Design and Performance of a High-Q Narrow Bandwidth Bandpass Filter in Empty Substrate Integrated Coaxial Line at Ku-Band

[EN] This letter presents the design and performance of a planar narrow bandwidth bandpass filter with high quality factor. The structure is composed of an empty substrate integrated coaxial line with the center conductor suspended in air. The component dimensions have been calculated by means of classical microwave filter design theory. The filter has been manufactured using standard printed circuit board fabrication processes. A measured insertion loss of 1.59 dB, 2.93% fractional bandwidth, and a Q-factor of 1505 have been obtained at 15 GHz. A Q-factor comparison with other substrate and empty substrate integrated technologies shows the advantages of the solution considered in this letter. The proposed filter proves to be suitable for the implementation of integrated microwave or millimeterwave subsystems with severe restrictions, i.e., low in-band losses, very narrow bandpass responses, low frequency dispersion, high out-of-band rejection, and low manufacturing cost.This work was supported by the Ministerio de Ciencia e Innovacion, Spanish Goverment, under Project TEC2016-75934-C4-X-R and Project TEC2016-75934-C4-1-R.Lucas Borja, A.; Belenguer, A.; Esteban González, H.; Boria Esbert, VE. (2017). Design and Performance of a High-Q Narrow Bandwidth Bandpass Filter in Empty Substrate Integrated Coaxial Line at Ku-Band. IEEE Microwave and Wireless Components Letters. 27(11):977-979. https://doi.org/10.1109/LMWC.2017.2750118S977979271

Krylov's solver based technique for the cascade connection of multiple n-port multimodal scattering matrices

“© 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.”In this paper, a novel technique for cascading generalized scattering matrices based on a Krylov's iterative solver is presented. This new technique is fully general, since it can be applied to solve the connection of an arbitrary number of networks, each one with an arbitrary number of ports, and it is easy to implement. This technique is able to compute, not only the modal spectra at the free ports of the global network, but also the modal spectra at the connected ports, so that the field inside the full network can be computed for an arbitrary incidence. In addition, this technique can also be used to evaluate the scattering parameters of the global network.Belenguer Martínez, Á.; Díaz Caballero, E.; Esteban González, H.; Lucas Borja, A.; Cascon Lopez, J. (2013). Krylov's solver based technique for the cascade connection of multiple n-port multimodal scattering matrices. IEEE Transactions on Microwave Theory and Techniques. 61(2):720-726. doi:10.1109/TMTT.2012.2231696S72072661

Highly efficient heterogeneous modal superposition method for the full-wave analysis of arbitrarily shaped H-plane structures fed through rectangular waveguides

This paper is a preprint of a paper submitted to IET Microwaves Antennas and Propagation and is subject to Institution of Engineering and Technology Copyright. If accepted, the copy of record will be available at IET Digital LibraryA new fully modal characterisation procedure is proposed to reduce the number of unknowns needed to characterise the ports of an arbitrary H-plane device in rectangular waveguide, so that no equivalent currents will be involved in the characterisation of the ports. Moreover, since no currents are needed to characterise the ports, the weights of the scattered modes can be unknowns of the resulting system of equations. This is an important fact, since, to find the wanted modal weights, a subsequent projection step is not necessary anymore. The new method is then advantageous when compared to other hybrid alternatives in the literature, not only because the ports are solved using fewer unknowns, which is the main advantage of the proposal, but also because the scattering parameters can be computed directly, once the system of equations is posed.This work was supported by Ministerio de Ciencia e Innovacion, Spanish Government, under Research Project TEC2007-67630-C03-01 and by the Autonomous Government of Castilla-La Mancha under Research Project PPII10-0047-0220.Belenguer Martínez, Á.; Esteban González, H.; Boria Esbert, VE.; Lucas Borja, A.; Cascón López, J. (2011). Highly efficient heterogeneous modal superposition method for the full-wave analysis of arbitrarily shaped H-plane structures fed through rectangular waveguides. IET Microwaves Antennas and Propagation. 5(7):747-755. https://doi.org/10.1049/iet-map.2010.0297S74775557Thiele, G., & Newhouse, T. (1975). A hybrid technique for combining moment methods with the geometrical theory of diffraction. IEEE Transactions on Antennas and Propagation, 23(1), 62-69. doi:10.1109/tap.1975.1141004Burnside, W.D., and Pathak, P.H.: ‘A summary of hybrid solutions involving moment methods and GTD’, Strait, B.J., Applications of the method of moments to electromagnetic fields, (SCEEE Press, St. Cloud, FL 1980), p. 629–636Theron, I. P., Davidson, D. B., & Jakobus, U. (2000). Extensions to the hybrid method of moments/uniform GTD formulation for sources located close to a smooth convex surface. IEEE Transactions on Antennas and Propagation, 48(6), 940-945. doi:10.1109/8.865227Dong-Ho Han, Polycarpou, A. C., & Balanis, C. A. (2002). Hybrid analysis of reflector antennas including higher order interactions and blockage effects. IEEE Transactions on Antennas and Propagation, 50(11), 1514-1524. doi:10.1109/tap.2002.803952Tiberi, G., Rosace, S., Monorchio, A., Manara, G., & Mittra, R. (2003). Electromagnetic scattering from large faceted conducting bodies by using analytically derived characteristic basis functions. IEEE Antennas and Wireless Propagation Letters, 2, 290-293. doi:10.1109/lawp.2003.822203Belenguer, A., Esteban, H., Boria, V. E., Bachiller, C., & Morro, J. V. (2010). Hybrid Mode Matching and Method of Moments Method for the Full-Wave Analysis of Arbitrarily Shaped Structures Fed Through Canonical Waveguides Using Only Electric Currents. IEEE Transactions on Microwave Theory and Techniques, 58(3), 537-544. doi:10.1109/tmtt.2010.2040353Wu, X. H., & Kishk, A. A. (2008). Hybrid of Method of Moments and Cylindrical Eigenfunction Expansion to Study Substrate Integrated Waveguide Circuits. IEEE Transactions on Microwave Theory and Techniques, 56(10), 2270-2276. doi:10.1109/tmtt.2008.2004255Balanis, C.A.: ‘Antenna theory: analysis and design’, 2nd(John Wiley & Sons, Inc., New York 1997)Clemmow, P.C.: ‘The plane wave spectrum representation of electromagnetic fields’, (IEEE Press/OUP 1996),ser. IEEE Press/OUP Series on Electromagnetic Wave TheoryHarrington, R.F.: ‘Field computation by moment methods’, (IEEE Press/OUP 1993),ser. IEEE Press/OUP Series on Electromagnetic Wave TheoryMorro, J. V., Esteban, H., Boria, V. E., Bachiller, C., & Belenguer, A. (2008). Optimization techniques for the efficient design of low-cost satellite filters considering new light materials. International Journal of RF and Microwave Computer-Aided Engineering, 18(2), 168-175. doi:10.1002/mmce.20264Marcuvitz, N.: ‘Waveguide handbook’, (IEE Electromagnetic Wave Series 21, London 1986)Peterson, A.F., Ray, S.L., and Mittra, R.: ‘Computational methods for electromagnetics’, (IEEE Press/OUP 1997),ser. IEEE Press/OUP Series on Electromagnetic Wave TheoryBachiller, C., Gonzalez, H. E., Esbert, V. E. B., Martinez, A. B., & Morro, J. V. (2007). Efficient Technique for the Cascade Connection of Multiple Two-Port Scattering Matrices. IEEE Transactions on Microwave Theory and Techniques, 55(9), 1880-1886. doi:10.1109/tmtt.2007.90407

Exercise Training as a Treatment for Cardiometabolic Risk in Sedentary Adults: Are Physical Activity Guidelines the Best Way to Improve Cardiometabolic Health? The FIT-AGEING Randomized Controlled Trial

This 12-week randomized controlled trial investigates the effects of different training modalities on cardiometabolic risk in sedentary, middle-aged adults, and examines whether alterations in cardiometabolic risk are associated with changes in those health-related variables that are modifiable by exercise training. The study subjects were 71 middle-aged adults (~54 years old; ~50% women) who were randomly assigned to one of the following treatment groups: (1) no exercise (control group), (2) concurrent training based on international physical activity recommendations (PAR group), (3) high intensity interval training (HIIT) group, or (4) HIIT plus whole-body electromyostimulation (HIIT+EMS group). A cardiometabolic risk score was calculated based on the International Diabetes Federation’s clinical criteria. A significant reduction in cardiometabolic risk was observed for all exercise training groups compared to the control group (all p < 0.05), which persisted after adjusting potential confounders (all p < 0.05). However, the HIIT+EMS group experienced the most significant reduction (p < 0.001). A significant inverse relationship was detected between the change in lean mass and the change in cardiometabolic risk (p = 0.045). A 12-week exercise training programs-especially the HIIT+EMS program-significantly reduced cardiometabolic risk in sedentary, middle-aged adults independent of sex, age, and cardiorespiratory fitness.The study was supported by the Spanish Ministry of Education (FPU14/04172 and FPU15/03960), by the University of Granada Plan Propio de Investigación 2016 (Excellence actions: Unit of Excellence on Exercise and Health [UCEES]) and Plan Propio de Investigación 2019-Programa Contratos-Puente, by the Junta de Andalucía, Consejería de Conocimiento, Investigación y Universidades, by the European Regional Development Fund (ERDF), ref. SOMM17/6107/UGR and by Redes Temáticas de Investigación Cooperativa RETIC grant Red SAMID RD16/0022

Stop Band Continuous Profile Filter in Empty Substrate Integrated Coaxial Line

[EN] Substrate integrated waveguides reduce the losses and increase the quality factor of resonators in communication filters when compared with traditional planar technologies, while maintaining their low-cost and low-profile characteristics. Empty substrate integrated waveguides go one step further, removing the dielectric of the substrate. One of these transmission lines is the empty substrate integrated coaxial line (ESICL), which has the advantage of being a two-conductor structure. Thus, it propagates a transversal electric and magnetic (TEM) mode, which reduces the dispersion and the bandwidth limitation of other one conductor empty substrate integrated waveguides. Continuous profile filters, at the cost of being long structures, are very easy to manufacture and design (usually no optimization is needed), and they are highly insensitive to manufacturing tolerances. In this work, a simple continuous profile filter, with a stop band response, is designed for the first time using novel ESICL technology. The influence of the design parameters on the insertion losses and fractional bandwidth is discussed. A prototype has been successfully manufactured and measured. A sensitivity analysis shows the high tolerance of the proposed stop band filter to manufacturing errors.This research was funded by Ministerio de Economia, Industria y Competitividad, Spanish Government, under Research Projects TEC2016-75934-C4-3-R and TEC2016-75934-C4-1-R.Gómez, D.; Esteban González, H.; Belenguer Martínez, Á.; Boria Esbert, VE.; Lucas Borja, A. (2018). Stop Band Continuous Profile Filter in Empty Substrate Integrated Coaxial Line. Applied Sciences (Basel). 8(11):1-12. https://doi.org/10.3390/app8112176S11281

Systematic Procedure to Avoid Unintended Polarity Mismatch in the Cascade Connection of Multiport Devices with Symmetric Feeding Lines

This paper is a postprint of a paper submitted to and accepted for publication in [journal] and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital LibraryThe traditional cascading of generalised scattering matrices (GSMs) assumes that the modal sets at the connected ports of a cascaded network are strictly equal. This implies a careful selection of the modal polarities, or the reference systems, of every port. Usually, the connection scheme of every device is known a priori. Then, the individual GSMs are pre-processed, or auxiliary devices, which correct possible modal mismatches at the ports, are included in appropriate positions among the cascade, so that the traditional cascading-by-pairs approach can be directly applied. This scheme clearly complicates the reutilisation of previously calculated GSMs, and mixes the cascading with the solution of the individual building blocks. In this study, a systematic procedure is proposed to define the polarity of the modes at the ports of a device fed with transmission lines or waveguides showing a single or double symmetry. The modified expressions to calculate the scattering parameters of the cascade of two multiport devices, incorporating the regular modal corrections to apply when this criterion is used to define the modal polarity at the ports, is also presented in this study. This strategy is more convenient from the point of view of programming, less error-prone and easier to implement.This work was supported by the Ministry of Science and Innovation, Spanish Government, under Research Projects TEC2013-47037-C05-3-R and TEC2013-47037-C05-1-R.Belenguer Martínez, Á.; Borja, A.; Díaz Caballero, E.; Esteban González, H.; Boria Esbert, VE. (2015). Systematic Procedure to Avoid Unintended Polarity Mismatch in the Cascade Connection of Multiport Devices with Symmetric Feeding Lines. IET Microwaves Antennas and Propagation. 9(11):1128-1135. https://doi.org/10.1049/iet-map.2014.0167S1128113591

Exploring the influence of vegetation cover, sediment storage capacity and channel dimensions on stone check dam conditions and effectiveness in a large regulated river in México

Check dams are widely used for soil conservation at the watershed scale. When structurally sound, these engineering control works retain sediment as planned. However, there is limited information describing the influence of site characteristics on post-construction condition including structural stability and sediment retention capacity. More specifically, the effects of channel morphology, check dam geometry and vegetation characteristics as potentially influencing factors on sediment retention capacity at the watershed level are poorly understood. Thus, an investigation applying field and remotely sensed measurements, multi-regression models, redundancy and sensitivity analysis, and correlation analysis was conducted in a Mexican watershed where the characteristics of 273 check dams were evaluated 3-5 years after construction. Vegetation cover and dimensions of the channel were found to be the most important factors influencing check dam fate. Taller structures experienced the greatest failure risk, in contrast to lower and wider structures and associated vegetation cover that retained long and wide sediment wedges, which helped to stabilise the check dams. The potential sediment storage capacity of the check dams mainly depends on the downstream height of the structure, but also on the vegetation cover near the structure walls; check dams constructed across a range of channel dimensions are able to effectively store sediment. Overall, this study provides a quantitative evaluation of the dominant factors influencing the post-construction conditions of check dams and their ability to store sediment, and thus provides land managers insights into the best strategies for soil conservation at the watershed scale using check dams

Broadband Equivalent Circuit Model for a Coplanar Waveguide Line Loaded with Split Ring Resonators

A new equivalent circuit for a coplanar waveguide loaded with split ring resonators is presented. The traditional circuits that model these devices are only able to characterize the left-handed propagation band, and their response is very similar to the real one within a very limited bandwidth. In contrast, this proposed broadband equivalent circuit is able to portray not only the left-handed propagation band, but also the right-handed one that occurs at higher frequencies. Besides, the response of this kind of basic cells can be adjusted with the proposed circuit model in a bandwidth close to a decade.This work was supported by the Ministerio de Ciencia e Innovacion, Spanish Goverment, under Research Projects TEC2010-21520-C04-03 and -01, and by the Autonomous Government of Castilla-La Mancha under Research Projects PPII10-0047-0220 and PPII10-0027-1277.Sanz, V.; Belenguer Martínez, Á.; Lucas Borja, A.; Cascón López, J.; Esteban González, H.; Boria Esbert, VE. (2012). Broadband Equivalent Circuit Model for a Coplanar Waveguide Line Loaded with Split Ring Resonators. International Journal of Antennas and Propagation. 2012:1-6. https://doi.org/10.1155/2012/613518S162012Baena, J. D., Bonache, J., Martin, F., Sillero, R. M., Falcone, F., Lopetegi, T., … Sorolla, M. (2005). Equivalent-circuit models for split-ring resonators and complementary split-ring resonators coupled to planar transmission lines. IEEE Transactions on Microwave Theory and Techniques, 53(4), 1451-1461. doi:10.1109/tmtt.2005.845211Borja, A. L., Carbonell, J., Boria, V. E., & Lippens, D. (2008). Symmetrical frequency response in a split ring resonator based transmission line. Applied Physics Letters, 93(20), 203505. doi:10.1063/1.3025625Borja, A. L., Carbonell, J., Boria, V. E., & Lippens, D. (2009). Highly selective left-handed transmission line loaded with split ring resonators and wires. Applied Physics Letters, 94(14), 143503. doi:10.1063/1.3116647Martı́n, F., Bonache, J., Falcone, F., Sorolla, M., & Marqués, R. (2003). Split ring resonator-based left-handed coplanar waveguide. Applied Physics Letters, 83(22), 4652-4654. doi:10.1063/1.1631392Aznar, F., Bonache, J., & Martín, F. (2008). Improved circuit model for left-handed lines loaded with split ring resonators. Applied Physics Letters, 92(4), 043512. doi:10.1063/1.2839600Roglá, L. J., Carbonell, J., & Boria, V. E. (2007). Study of equivalent circuits for open-ring and split-ring resonators in coplanar waveguide technology. IET Microwaves, Antennas & Propagation, 1(1), 170. doi:10.1049/iet-map:20050340Borja, A. L., Carbonell, J., Boria, V. E., Cascon, J., & Lippens, D. (2010). A 2% Bandwidth C-Band Filter Using Cascaded Split Ring Resonators. IEEE Antennas and Wireless Propagation Letters, 9, 256-259. doi:10.1109/lawp.2010.2046711Gil, M., Bonache, J., Garcia-Garcia, J., Martel, J., & Martin, F. (2007). Composite Right/Left-Handed Metamaterial Transmission Lines Based on Complementary Split-Rings Resonators and Their Applications to Very Wideband and Compact Filter Design. IEEE Transactions on Microwave Theory and Techniques, 55(6), 1296-1304. doi:10.1109/tmtt.2007.897755Shamonin, M., Shamonina, E., Kalinin, V., & Solymar, L. (2004). Resonant frequencies of a split-ring resonator: Analytical solutions and numerical simulations. Microwave and Optical Technology Letters, 44(2), 133-136. doi:10.1002/mop.2056

Slotted ESIW Antenna with high efficiency for a MIMO Radar Sensor

[EN] This paper introduces a slotted empty substrate integrated waveguide (ESIW) antenna for a multiple-input multiple-output (MIMO) radar sensor. The proposed system is based on the MIMO radar architecture. Orthogonal signals are sent from the transmitters, in such a manner that a MIMO image reconstruction is possible. The presented system application targets the surveillance of strategic areas in gas pipelines and nuclear plants. ESIW technology enables a high-efficiency, low-profile, and compact antenna for these MIMO systems. The fabricated device includes a transition to microstrip line, and, in consequence, the antenna can be integrated with the rest of the system in a standard integrated circuit. The slotted ESIW antenna design and measured results for the targeted application are presented in this paper. The measured results present a gain greater than 15 dBi and return loss below ¿13 dB over the targeted frequency band of operation (16¿16.5 GHz). To the best of the authors¿ knowledge, this is the first slotted ESIW antenna reported in the scientific literature up to now.This work was supported by the Ministerio de Economia y Competitividad, Spanish Government, under research projects TEC2016-75934-C4-3-R and TEC2016-75934-C4-1-R.Miralles-Navarro, E.; Belenguer Martinez, A.; Mateo Sotos, J.; Torres Aranda, AM.; Esteban González, H.; Lucas Borja, A.; Boria Esbert, VE. (2018). Slotted ESIW Antenna with high efficiency for a MIMO Radar Sensor. Radio Science. 53(5):605-610. https://doi.org/10.1002/2017RS006461S60561053