Passive devices for UWB systems

Postprint (published version

EH Performance of an Hybrid Energy Harvester for Autonomous Nodes

This paper reports the Energy Harvesting (EH) performance of a hybrid energy harvester able to collect energy form different energy sources: thermal, solar and electromagnetic. The main block of the system is the quarter-wavelength patch antenna, operating in the Industrial, Scientific and Medical (ISM) frequency band 2.4-2.5 GHz. The antenna has been designed and optimized to support a Thermo-Electric Generator (TEG) and a Solar Cell on its top. Moreover, a rectifier has been designed to work with the antenna and a DC-DC converter has been used to manage the TEG output voltage

Goal Preferences, Affect, Activity Patterns and Health Outcomes in Women With Fibromyalgia

Some motivational models understand health behavior as a result of the interaction between goal preferences and mood. However, this perspective has not been explored in fibromyalgia. Furthermore, in chronic pain, it has only been explored with regard to negative affect. Thus, our aims were: (1) to develop a Spanish version of the Goal Pursuit Questionnaire (GPQ); (2) to explore the relationships between goal preferences and health outcomes, testing the moderator role of affect and the mediating role of chronic pain activity patterns. We conducted two cross-sectional studies. In Study 1, after a double translation/back-translation process, we interviewed 94 women attending the Fibromyalgia Unit of the Community of Valencia in order to identify the cultural feasibility and the content validity of the GPQ. Study 2 comprised 260 women. We explored the GPQ structure and performed path analyses to test conditional mediation relationships. Eight activities from the original GPQ were changed while maintaining the conceptual equivalence. Exploratory factor analysis showed two factors: ‘Painavoidance goal’ and ‘Mood-management goal’ (37 and 13% of explained variance, respectively). These factors refer to patients’ preference for hedonic goals (pain avoidance or mood-management) over achievement goals. Robust RMSEA fit index of the final models ranged from 0.039 for pain to 0.000 for disability and fibromyalgia impact. Pain avoidance goals and negative affect influenced pain mediated by taskcontingent persistence. They also affected disability mediated by task and excessive persistence. Pain avoidance goals and positive affect influenced fibromyalgia impact mediated by activity avoidance. We also found a direct effect of negative and positive affect on health outcomes. Preference for pain avoidance goals was always related to pain, disability and fibromyalgia impact through activity patterns. Affect did not moderate these relationships and showed direct and indirect paths on health outcomes, mainly by increasing persistence and showing positive affect as an asset and not a risk factor. Intervention targets should include flexible reinforcement of achievement goals relative to pain avoidance goals and positive affect in order to promote task-persistence adaptive activity patterns and decreased activity avoidance

Predicting Abusive Behaviours in Spanish Adolescents’ Relationships: Insights from the Reasoned Action Approach

(1) Background: Partner violence prevention programmes do not produce the expected behavioural changes. Accordingly, experts suggest applying evidence-based behavioural models to identify the determinants of abusive behaviours. In this research, we applied the reasoned action approach (RAA) to predict the performance (boys) and acceptance (girls) of abusive behaviours in adolescents. (2) Method: We designed a questionnaire based on the RAA and performed a crosssectional study. We analysed the predictive capacity of the RAA constructs on intentions with the sample of single adolescents (n = 1112). We replicated the analysis only with those who were in a relationship (n = 587) and in addition analysed the predictive capacity of intention on future behaviour (3 months later). (3) Results: The hierarchical regression analysis performed with the sample of single adolescents showed that the model explained 56% and 47% of the variance of boys’ intentions to perform the controlling and devaluing behaviours, respectively; and 62% and 33% of girls’ intention to accept them. With those in a relationship, the model explained 60% and 53% of the variance of boys’ intentions to perform the controlling and devaluating behaviour, respectively, and 70% and 38% of girls’ intention to accept them. Intention exerted direct effects on boys’ performance of controlling and devaluing behaviours (31% and 34% of explained variance, respectively) and on girls’ acceptance (30% and 7%, respectively). (4) Conclusions: The RAA seems useful to identify the motivational determinants of abusive behaviours, regardless of adolescents´ relationship status, and for their prediction. Perceived social norms emerge as a relevant predictor on which to intervene to produce behavioural changes with both sexe

Promoting unsupervised walking in women with fibromyalgia: a randomized controlled trial

The objective of this study is to test the efficacy of a group motiva-tional plus implementation intentions intervention in promoting adherence to an unsupervised walking program recommended for fibromyalgia, compared to an implementation intentions condition and to an active control condition. A triple-blind, randomized, long-itudinal study with measures at baseline, short (seven weeks post- intervention), mid (12 weeks) and long-term (36 weeks) is performed. Data are analyzed using multilevel longitudinal growth curve two- level modelling. Participants are 157 women with fibromyalgia. In the short-term, adherence to the minimum and to the standard walking program (primary outcome measures) is explained by time (both p <.001), motivational plus implementation intentions intervention (both p <.001) and by their interaction (both p <.001). Regarding the secondary outcomes, only physical function is explained by time (p <.001), motivational plus implementation intentions intervention (p <.05) and by their interaction (p <.05). Motivational plus imple-mentation intentions intervention achieve the promotion of walking as an exercise in the short-term; furthermore, physical function of the women in this condition is better than in the other two intervention groups, which is a relevant outcome from a rehabilitation point of view. However, more studies are needed to maintain the exercise at mid and long-term

Broad band analysis of arbitrarily shaped microwave filters using a novel singular value decomposition technique

A new full-wave electromagnetic analysis method based on the Boundary Integral Resonant Mode Expansion (BI-RME) is presented in this paper. The technique allows the computation of the broad band circuital response of arbitrarily shaped cavity filters. The coaxial excitation of this kind of filters is rigorously modeled by taking into account the high order modes on the coaxial aperture. A singular decomposition algebraic procedure has been implemented in order to obtain the solenoidal and non-solenoidal counterparts contributions of the electric current density inside the cavity needed by the BI-RME formulation. This method is simple and avoids some issues associated to star and loop based functions which are typically used for the same purpose.This work has been developed with financial support fromSENECA project Ref. 08833/PI/08, and CICYT project Ref.TEC2007-67630-C03

Wideband generalized admittance matrix representation for the analysis and design of waveguide filters with coaxial excitation

A very efficient technique for the full-wave analysis and design of complex passive waveguide filters, including rectangular cavities with metallic cylindrical posts and coaxial excitation, is presented. This novel technique provides the wideband generalized admittance matrix representation of the whole structure in the form of pole expansions, thus extracting the most expensive computations from the frequency loop. For this purpose, the structure is properly segmented into its key building blocks, all of them characterized in terms of wideband admittance matrices. Then, an efficient iterative algorithm for combining these matrices, and finally providing the wideband generalized admittance matrix of the complete structure, is followed. In order to validate the accuracy and efficiency of this full-wave modal technique, four different waveguide filters have been considered. In particular, the design of a compact four-pole in-line filter with tuning screws and of an evanescent-mode filter, both operating in the X-band and including a standard (vertical) coaxial excitation, are first presented. Finally, two C-band six-resonator comb-line filters, one of them with a cross-coupling configuration, and both excited with a collinear end-launcher transition based on a disc-ended coaxial, are also designed. Numerical data from a commercial software, as well as measurements of a manufactured prototype, are included for verification purposes.Mira Pérez, FE.; San Blas Oltra, ÁA.; Boria Esbert, VE.; Rogla Madrid, LJ.; Gimeno Martinez, B. (2013). Wideband generalized admittance matrix representation for the analysis and design of waveguide filters with coaxial excitation. Radio Science. 48:1-11. doi:10.1002/rds.20013S11148Alessandri, F., Bartolucci, G., & Sorrentino, R. (1988). Admittance matrix formulation of waveguide discontinuity problems: computer-aided design of branch guide directional couplers. IEEE Transactions on Microwave Theory and Techniques, 36(2), 394-403. doi:10.1109/22.3528Alessandri, F., Mongiardo, M., & Sorrentino, R. (1992). Computer-aided design of beam forming networks for modern satellite antennas. IEEE Transactions on Microwave Theory and Techniques, 40(6), 1117-1127. doi:10.1109/22.141343Arcioni, P., & Conciauro, G. (1999). Combination of generalized admittance matrices in the form of pole expansions. IEEE Transactions on Microwave Theory and Techniques, 47(10), 1990-1996. doi:10.1109/22.795073Arcioni, P., Bozzi, M., Bressan, M., Conciauro, G., & Perregrini, L. (2002). Frequency/time-domain modelling of 3D waveguide structures by a BI-RME approach. International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, 15(1), 3-21. doi:10.1002/jnm.429Boria, V. E., Guglielmi, M., & Arcioni, P. (1998). Computer-aided design of inductively coupled rectangular waveguide filters including tuning elements. International Journal of RF and Microwave Computer-Aided Engineering, 8(3), 226-235. doi:10.1002/(sici)1099-047x(199805)8:33.0.co;2-hBozzi, M., Perregrini, L., & Wu, K. (2009). A novel technique for the direct determination of multimode equivalent circuit models for substrate integrated waveguide discontinuities. International Journal of RF and Microwave Computer-Aided Engineering, 19(4), 423-433. doi:10.1002/mmce.20360Chang, H.-C., & Zaki, K. A. (1991). Evanescent-mode coupling of dual-mode rectangular waveguide filters. IEEE Transactions on Microwave Theory and Techniques, 39(8), 1307-1312. doi:10.1109/22.85405Gentili, G. G. (2001). Multiport analysis of arbitrary circular-rod insets in rectangular waveguide by the generalized admittance matrix. IEEE Transactions on Microwave Theory and Techniques, 49(8), 1438-1442. doi:10.1109/22.939924Gimeno, B., & Guglielmi, M. (1997). Multimode equivalent network representation for junctions between coaxial and circular waveguides. International Journal of Microwave and Millimeter-Wave Computer-Aided Engineering, 7(2), 180-194. doi:10.1002/(sici)1522-6301(199703)7:23.0.co;2-wGuglielmi, M. (1994). Simple CAD procedure for microwave filters and multiplexers. IEEE Transactions on Microwave Theory and Techniques, 42(7), 1347-1352. doi:10.1109/22.299728Hoft, M., & Yousif, F. (2011). Orthogonal Coaxial Cavity Filters With Distributed Cross-Coupling. IEEE Microwave and Wireless Components Letters, 21(10), 519-521. doi:10.1109/lmwc.2011.2165533Ihmels , R. F. Arndt 1993 Field theory CAD of L-shaped iris coupled mode launchers and dual-mode filters IEEE MTT-S Int. Microw. Symp. DigLevy, R., Hui-Wen Yao, & Zaki, K. A. (1997). Transitional combline/evanescent-mode microwave filters. IEEE Transactions on Microwave Theory and Techniques, 45(12), 2094-2099. doi:10.1109/22.643743Liang, J.-F., Chang, H.-C., & Zaki, K. A. (1992). Coaxial probe modeling in waveguides and cavities. IEEE Transactions on Microwave Theory and Techniques, 40(12), 2172-2180. doi:10.1109/22.179878Mansour, R. R., & Macphie, R. H. (1986). An Improved Transmission Matrix Formulation of Cascaded Discontinuities and its Application to E-Plane Circuits. IEEE Transactions on Microwave Theory and Techniques, 34(12), 1490-1498. doi:10.1109/tmtt.1986.1133568Marcuvitz, N. (1986). Waveguide Handbook. doi:10.1049/pbew021eMira, F., Bressan, M., Conciauro, G., Martinez, B. G., & Esbert, V. E. B. (2005). Fast S-domain modeling of rectangular waveguides with radially symmetric metal insets. IEEE Transactions on Microwave Theory and Techniques, 53(4), 1294-1303. doi:10.1109/tmtt.2005.845762Mira , F. A. A. San Blas V. E. Boria B. Gimeno G. Conciauro 2005b Fast and accurate CAD tool of passive rectangular waveguide devices including cylindrical conducting posts Proc. 35th Eur. Microw. ConfMira , F. A. A. San Blas V. E. Boria B. Gimeno 2008 Efficient pole expansion of the generalized admittance matrix representation of planar waveguide junctions Proc. 38th Eur. Microw. ConfMira, F., San Blas, A. A., Boria, V. E., & Gimeno, B. (2009). Wideband impedance matrix representation of passive waveguide components based on cascaded planar junctions. Radio Science, 44(1), n/a-n/a. doi:10.1029/2008rs003886Morini, A., Venanzoni, G., & Rozzi, T. (2006). A new adaptive prototype for the design of side-coupled coaxial filters with close correspondence to the physical structure. IEEE Transactions on Microwave Theory and Techniques, 54(3), 1146-1153. doi:10.1109/tmtt.2005.864112Morini, A., Venanzoni, G., Farina, M., & Rozzi, T. (2007). Modified Adaptive Prototype Inclusive of the External Couplings for the Design of Coaxial Filters. IEEE Transactions on Microwave Theory and Techniques, 55(9), 1905-1911. doi:10.1109/tmtt.2007.904329Quesada , F. D. A. Vidal F. J. Pérez A. Berenguer A. A. San Blas F. Mira V. E. Boria B. Gimeno A. Álvarez 2010 Broad band analysis of arbitrarily shaped microwave filters using a novel singular value decomposition technique Proc. 4th Eur Conf. Ant. Prop. (EuCAP)San Blas , A. A. F. Mira V. E. Boria B. Gimeno G. Conciauro M. Bressan P. Arcioni 2006 Efficient CAD of generalized coaxial probes in rectangular waveguide using the 3D BI-RME method Proc. 36th Eur. Microw. ConfHui-Wen Yao, Zaki, K. A., Atia, A. E., & Hershtig, R. (1995). Full wave modeling of conducting posts in rectangular waveguides and its applications to slot coupled combline filters. IEEE Transactions on Microwave Theory and Techniques, 43(12), 2824-2830. doi:10.1109/22.47564

Full-wave analysis and design of broadband turnstile junctions

The efficient design of broadband turnstile junctions compensated with piled-up cylindrical metallic posts is discussed in this contribution. Very high relative bandwidths can be obtained, while maintaining the diameter of the input circular access port lower than the width of the rectangular waveguide ports, thus reducing the number of excited higher order circular waveguide modes. A novel full-wave analysis tool has also been implemented in order to reduce the CPU effort related to the complete design process.San Blas Oltra, ÁA.; Pérez Soler, FJ.; Gil Raga, J.; Mira Pérez, FE.; Boria Esbert, VE.; Gimeno Martinez, B. (2011). Full-wave analysis and design of broadband turnstile junctions. Progress In Electromagnetics Research Letters. 24:149-158. doi:10.2528/PIERL11051703S1491582

Exploring the Relationship Between the Acceptability of an Internet-Based Intervention for Depression in Primary Care and Clinical Outcomes: Secondary Analysis of a Randomized Controlled Trial

Background: Depression is one of the most prevalent psychological disorders worldwide. Although psychotherapy for depression is effective, there are barriers to its implementation in primary care in Spain. The use of the Internet has been shown to be a feasible solution. However, the acceptability of Internet-based interventions has not been studied sufficiently.Objective: To assess the acceptability of an Internet-based intervention (IBI) for depression in primary care, and explore the relationship between expectations and satisfaction and the improvement in the clinical variables in primary care patients receiving this intervention. Furthermore, it offers data about the effects of some sociodemographic characteristics on these acceptability variables and analyzes whether the expectations are related to finalizing the intervention.Methods: Data were based on depressive patients who were participants in a randomized controlled trial. In the present study, we present the data from all the participants in the Internet intervention groups (N = 198). All the participants filled out the expectation and satisfaction scales (six-item scales regarding treatment logic, satisfaction, recommending, usefulness for other disorders, usefulness for the patient, and unpleasantness), the Beck Depression Inventory-II, and the secondary outcome measures: depression and anxiety impairment, and positive and negative affect.Results: Results showed that participants’ expectations and satisfaction with the program were both high and differences in expectations and satisfaction depended on some sociodemographic variables (age: older people have higher expectations; sex: women have greater satisfaction). A positive relationship between these variables and intervention efficacy was found: expectations related to “usefulness for the patient” were a statistically related predictor to the results on the BDI-II (Beta = 0.364), and the perception of how logical the treatment is (Beta = 0.528) was associated with change in the clinical variable. Furthermore, the higher the expectations, the higher the improvements exhibited by the patients in all measures evaluated during the ten intervention modules. High expectations were also directly related to finalizing the intervention.Conclusions: This is the first study in Spain to address this issue in the field of IBIs for depression in primary care. The IBI showed high acceptance related to the intervention’s efficacy and completion. Research on IBI acceptability could help to implement the treatment offered.Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT01611818

Mechanical tuning of substrate integrated waveguide resonators

This letter presents a novel approach for providing substrate-integrated waveguide tunable resonators by means of placing an additional metalized via-hole on the waveguide cavity. The via-hole contains an open-loop slot on the top metallic wall. The dimensions, position and orientation of the open-loop slot defines the tuning range. Fabrication of some designs reveals good agreement between simulation and measurements. Additionally, a preliminary prototype which sets the open-loop slot orientation manually is also presented, achieving a continuous tuning range of 8%Peer ReviewedPostprint (published version