BUSCADOR RECOLECTA

Patients admitted to Intensive Care Units (ICU) are transported from and to other units. Knowing their location is strategic for a sound planning of intra-hospital transports as well as resources management. This is even more crucial in big hospital complexes, comprised of several buildings often connected through tunnels. In this work, a patient tracking application in a multi-building, tunnel-connected hospital complex (the Hospital Complex of Navarre) is presented. The system leverages Internet of Medical Things (IoMT) communication technologies, such as Long Range Wide-Area Network (LoRaWAN) and Near Field Communication (NFC). The locations of the LoRaWAN nodes were selected based on several factors, including the situation of the tunnels, buildings services and medical equipment and a literature review on intra-hospital ICU patients' trips. The possible locations of the LoRaWAN gateways were selected based on 3D Ray Launching Simulations, in order to obtain accurate characterization. Once the locations were set, a LoRaWAN radio coverage studio was performed. The main conclusion drawn is that just one LoRaWAN gateway would be enough to cover all overground LoRaWAN nodes deployed. A second one would be required for underground coverage. In addition, a remote, private cloud infrastructure together with a mobile application was created to manage the information generated. On-field tests were performed to assess the technical feasibility of the system. The application provides with on-demand ICU patients' movement flow around the complex. Although designed for the ICU-admitted patients' context, the system could be easily extrapolated to other use cases., This work was supported in part by the Project 'Arquitectura 'Internet of Medical Things' (IoMT) para la monitorización y gestión semántica de datos relativos a enfermedades cardiovasculares' funded by the Universidad Pública de Navarra under Grant PJUPNA29, in part by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE) under Project TEC2017-85529-C03-3R and Project RTI2018-095499-B-C31, and in part by the European Union's Horizon 2020 Research and Innovation Programme (Stardust-Holistic and Integrated Urban Model for Smart Cities) under Agreement N. 774094.

In this paper, the assessment of multiple scenario cases for large-scale farm monitoring using Low-Power Wide-Area Network (LPWAN) based near-ground sensor nodes with the interaction of both tractors and farmers are presented. The proposed scenario under analysis considers multiple communication links, namely nodes to infrastructure, nodes to tractor, nodes to farmer, tractor to infrastructure and farmer to infrastructure communications. Moreover, these scenarios are proposed for tractors and agricultural equipment performance improvement and tracking, as well as resources management within the farm field. Different link type configurations are tested in order to consider the impact of ground, spatial distribution as well as infrastructure elements. The results show that LPWAN-based WSNs can provide better performance in terms of coverage and radio link quality results than ZigBee for a non-flat large-scale farm field in both cases of near-ground fixed nodes and moving tractor and farmer. The proposed systems are validated by cloud-based platforms for LoRaWAN, Sigfox and NB-IoT communications, providing flexible and scalable solutions to enable interactive farming applications., This research is supported by the 2017 Predoctoral Research Grant supported by the Xunta de Galicia and the research projects TEC2017-85529-C03-3R and RTI2018-095499-B-C31, funded by Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU, AEI, FEDER, UE), as well as from European Union's Horizon 2020 research and Innovation programme under grant agreement N°774094 (Stardust-Holistic and Integrated Urban Model for Smart Cities).

In this paper we consider the D2D (Device-to-Device) communication taking place between Wireless Sensor Networks (WSN) elements operating in vegetation environments in order to achieve the radio channel characterization at 2.4 GHz, focusing on the radio links blocked by oak and pine trees modelled from specimens found in a real recreation area located within forest environments. In order to fit and validate a radio channel model for this type of scenarios, both measurements and simulations by means of an in-house developed 3D Ray Launching algorithm have been performed, offering as outcomes the path loss and multipath information of the scenarios under study for forest immersed isolated trees and non-isolated trees. The specific forests, composed of thick in-leaf trees, are called Orgi Forest and Chandebrito, located respectively in Navarre and Galicia, Spain. A geometrical and dielectric model of the trees were created and introduced in the simulation software. We concluded that the scattering produced by the tree can be divided into two zones with different dominant propagation mechanisms: an obstructed line of sight (OLoS) zone far from the tree fitting a log-distance model, and a diffraction zone around the edge of the tree. 2D planes of delay spread value are also presented which similarly reflects the proposed two-zone model., This research was funded by Xunta de Galicia under grant ED431C-2019/26, Spanish Government under grant TEC2017-85529-C03-3R, AtlantTIC Research Center and project RTI2018-095499-B-C31, Funded by Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER, UE).

In this paper, a novel waffle-iron filter with
transmission zeros at multiple frequencies, along with its design
procedure, is presented. The proposed filter features a high-power
behavior and a wide rejected band in a single compact structure
by means of a set of transmission zeros that can also be placed close
to the passband. Its design method rests on a divide-and-rule
strategy, where the physical dimensions of the constituent design
entities (DEs) can be easily computed in a very short time. A novel
high-power compact waffle-iron filter with transmission zeros at
multiple frequencies has been designed as well as several classical
waffle-iron filters with transmission zeros at one frequency only,
using a detailed step-by-step procedure which avoids the bruteforce
optimizations needed until now. Multipactor and corona
simulations have been conducted proving a high-power handling
capability of 1.8 kW and 78.6 W, respectively. A prototype of the
novel filter has been fabricated, obtaining a remarkable
accordance between the simulated and measured results., This work was supported in part by the ESA’s
Networking/Partnering Initiati
ve under Contract 4000114859/15/NL/HK and
in part by the MINECO (Spain) under Project TEC2017-85529-C3-2-R,
Project TEC2014-55735-C3-R, and Project TEC2014-51902-C2-2-R. This
paper is an expanded version from the
2018 International Microwave Sym-
posium, Philadelphia, PA, USA, June 10–15 2018.
(Corresponding author:
Fernando Teberio.)

To design a filter for a particular application, many issues must first be considered. Which technology will be the most convenient? What design technique will provide better results for a particular set of frequency specifications? Once the device has been designed, will it fulfill all of the (not only electrical) requirements? It is not always easy to answer such questions in advance. In this article, we try to shed some light on these questions when our aim is the design of filters for high-power operation., This article covers work supported by the Spanish Ministerio de Ciencia, Innovación y Universidades–Agencia Estatal de Investigación under Project TEC2017-85529-C3-2-R (AEI, FEDER-EU).

Recently, there has been growing attention to the power grid management due to the increasing concerns on global warming. With the advancement in electric vehicles (EV) industry and the evolution in batteries, EVs become an important contributor to the grid with capability of bidirectional power exchange with the grid. In this context, Vehicle-to-Grid (V2G) systems enable multiple functionalities between EVs and the corresponding aggregator. Thus, reliable, long-range communication capabilities between aggregator and EVs is compulsory. In this paper, wireless channel analysis for aggregator and electrical vehicle communication using Long-Range Wide Area Network (LoRaWAN) technology in V2G is presented, in order to test a low-cost solution with large coverage and reduced power consumption profile. Wireless channel and system-level measurements have been performed in a real urban scenario between EV's charging station in Pamplona (Spain) and a vehicle in motion using LoRaWAN 868 MHz devices. Wireless channel characterization is performed by implementing a full 3D urban scenario model, including elements such as buildings, vehicles, users and urban infrastructure such as lamp posts and benches. By means of in-house developed 3D Ray Launching algorithm with hybrid simulation capabilities, estimations of received power levels, signal to noise ratio and time domain parameters have been obtained, for the complete volume of the scenario under test in dense urban conditions. V2G end to end communication has been validated by implementing an intra-vehicle Controller Area Network-BUS (CAN BUS) data gathering system connected to the vehicle LoRaWAN transceiver and subsequently, to a cloud-based web service. The results show that the accurate deterministic based radio channel analysis enables to optimize the network design of LoRaWAN networks in a vehicular environment, considering inter-vehicular and infrastructure links, enabling scalable, low cost end to end data exchange for the deployment of ancillary V2G services., This work was supported in part by the 2017 Predoctoral Research Grant through the Xunta de Galicia and the Research Projects funded by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España through Ministerio de Ciencia, Innovación y Universidades (MCIU)/Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER)/Unión Europea (UE) under Grant TEC2017-85529-C03-3R and Grant RTI2018-095499-B-C31, and in part by the European Union’s Horizon 2020 Research and Innovation Program (Stardust-Holistic and Integrated Urban Model for Smart Cities) under Grant N◦774094.

A compact high-power low-pass filter for C-band broadband satellite applications is presented in this paper. The filter is composed of three different sections. A 9th-order compact high-power multi-ridge structure achieves the fundamental mode stopband and the suppression of all-higher order modes. The required slope between the pass- and the stopband is accomplished by means of two step-shaped bandstop elements separated by very short waveguide sections. The passband of the filter is achieved through two compact matching networks. The filter is only 164-mm long, has less than 0.05 dB of insertion loss, handles 9.6 kW (single-carrier multipactor analysis), and has a very wide stopband (up to Ku-band). A dramatic size reduction has been achieved with respect to other commercially available solutions., This work was supported by the Spanish Ministerio de Ciencia, Innovación y Universidades – Agencia Estatal de Investigación under Project TE2017-85529-C3-2-R (AEI, FEDER-EU).

In this paper, a novel design method for rectangular waveguide filters intended for fabrication using direct metal additive manufacturing is proposed. The synthesized filters will feature a smooth profile that allows us to fabricate them orienting the filter propagation axis in the vertical building direction, achieving an optimum configuration for direct metal additive manufacturing fabrication. The novel design method is valid for any all-pole transfer function, which is initially implemented with a commensurate-line distributed unit element prototype. The impulse response of that initial prototype is then properly interpolated to obtain the target response for a smooth-profiled filter with similar length and profile excursion. Finally, the target impulse response just generated is implemented in rectangular waveguide technology employing a novel inverse scattering synthesis technique that relies on the coupled-mode theory to model the electromagnetic behavior of the waveguide filter. The novel inverse scattering synthesis technique is general and also valid for the case of filters with very high rejection levels, which is of great relevance in rectangular waveguide technology. A Ku-band low-pass filter with stringent satellite specifications is designed using the proposed method, fabricated by means of a direct metal additive manufacturing technique, and measured with a vector network analyzer. A very good agreement is achieved between the simulated and measured results, fulfilling the required specifications and demonstrating the feasibility and performance of the novel design method., This
work was supported in part by the Spanish Ministerio de Ciencia e
Innovación—Agencia Estatal de Investigación (MCIN/AEI/10.13039/
501100011033) under Project TEC2017-85529-C3-2-R (co-funded by
the Fondo Europeo de Desarrollo Regional (FEDER) “A way to make
Europe”) and Project PID2020-112545RB-C53, and in part by the Advanced
Technologies for future European Satellite Applications (TESLA) Project
(European Union’s Horizon 2020 Research and Innovation Programme
through the Marie Sklodowska-Curie Grant) under Grant 811232.

A rectangular waveguide bandpass filter for Q-band with simple fabrication is proposed in this letter. The design is based on the use of the first passband replica of commensurate-line stepped-impedance structures and achieves the suppression of their inherent low-pass response. In order to do it, the filter is implemented by rectangular waveguide sections with different widths and heights that can be analytically calculated. The technique is validated by a 9th order Chebyshev filter with passband between 40 and 43 GHz and fabrication yield equal to 84 % for a manufacturing error of ± 20 μm. The measured results of the prototype fabricated with CNC milling are in good agreement with the simulated ones., This work was supported by the Spanish
Ministerio de Ciencia, Innovación y Universidades–Agencia Estatal de
Investigación under Project TEC2017-85529-C3-2-R (AEI, FEDER-EU) and
by the European Union’s Horizon 2020 research and innovation programme
under grant agreement no. 811232-TESLA-H2020-MSCA-ITN-2018.

In this paper, a new topology for rectangular
waveguide bandpass and low-pass filters is presented. A simple,
accurate, and robust design technique for these novel meandered
waveguide filters is provided. The proposed filters employ a
concatenation of ±90° E-plane mitered bends (±90° EMBs) with
different heights and lengths, whose dimensions are consecutively
and independently calculated. Each ±90° EMB satisfies a local
target reflection coefficient along the device so that they can
be calculated separately. The novel structures allow drastically
reduce the total length of the filters and embed bends if
desired, or even to provide routing capabilities. Furthermore,
the new meandered topology allows the introduction of transmission
zeros above the passband of the low-pass filter, which can be
controlled by the free parameters of the ±90° EMBs. A bandpass
and a low-pass filter with meandered topology have been designed
following the proposed novel technique. Measurements of the
manufactured prototypes are also included to validate the novel
topology and design technique, achieving excellent agreement
with the simulation results., This work was supported by ESA’s Networking/Partnering Initiative (NPI)
under Contract 4000114859/15/NL/HK, Gobierno de Navarra under Project
0011-1365-2017-000130, and MINECO (Spain) under Projects TEC2014-
51902-C2-2-R and TEC2017-85529-C3-2-R.

A very simple design method to embed routing capabilities in classical corrugated filters
is presented in this paper. The method is based on the calculation of the heights and lengths of the
so-called filters design building blocks, by means of a consecutive and separate extraction of their local
reflection coefficients along the device. The proposed technique is proved with a 17th-order Zolotarev filter
whose topology is bent twice so that the input and output ports are in the same plane while
preserving the in-line filters behaviour. This new filter allows the possibility of eliminating subsequent
bending structures, reducing the insertion loss, weight, and PIM., This work was supported by MINECO (Spain) (grant TEC2014-55735-C3-R, TEC2014-51902-C2-2-R,
and TEC2017-85529-C3-2-R).

In this paper, a novel and general method to synthetize microwave waveguide tapers intended for single mode operation is proposed. The technique is based on the use of an exact series solution of the inverse scattering synthesis problem. An additional strategy necessary for dealing with waveguides where the propagation constant varies with the position is included. The coupled-mode theory is employed to model the electromagnetic behavior of the taper with the inherent mismatch caused by the connection of the waveguides with different cross-sections. The novel method allows us to synthesize the (classical) transmission line taper functions of Klopfenstein and Hecken, making them suitable for general waveguide tapers with single mode operation. Additionally, a new type of taper functions, also suitable for general waveguide tapers, is presented. The novel functions are obtained by partially employing the frequency response of multisection transformers, resulting in fully smooth tapers that can offer shorter lengths than the classical proposals. The taper synthesis procedure is demonstrated in rectangular waveguide technology, by requiring realistic and challenging specifications for different cases with different waveguide cross-sections to be matched: height mismatch, width mismatch, and simultaneous height and width mismatch. Several prototypes of Klopfenstein, Hecken and novel function tapers have been fabricated in an aluminum alloy by means of an Additive Manufacturing technique (Direct Metal Laser Sintering). The simulation and measurement results obtained for the rectangular waveguide taper prototypes confirm the accuracy of the novel synthesis technique proposed., This work was supported by the MINECO
(Spain) under project TEC2017-85529-C3-2-R (AEI, FEDER-EU).

In this contribution, an end to end system to enable user interaction with a distributed botanical university campus garden is designed, implemented and tested. The proposed system employs different wireless links to collect data related to different bio physiological parameters of both the vegetation mass and the surrounding environment. Detailed analysis of these multilevel communication links is performed by using deterministic volumetric wireless channel estimation and considering underground, near ground and over ground radio propagation conditions. An in-house developed technique enables accurate wireless channel characterization for complete campus scenario considering the multiple link types and all its composing elements. Node definition and network topology is thus obtained by wireless channel analysis of over ground, near ground and underground communication for both 868 MHz and 2.4 GHz Wireless Sensor Networks in an inhomogeneous vegetation environment. Connectivity to enable user interaction as well as for telemetry and tele-control purposes within the campus is achieved by combining ZigBee and LoRaWAN transceivers with the corresponding sensor/actuator platforms. Coverage studies have been performed in order to assess communication capabilities in the set of multiple underground/near ground/over ground links, by means of deterministic channel analysis for the complete university campus location. Measurement results in lab environment as well as full system deployment are presented, showing good agreement with deterministic simulations. Moreover, system level tests have been performed over a physical campus cloud, providing adequate quality of experience metrics. The proposed solution is a scalable system that provides real time trees status monitoring by a cloud-based platform, enabling user interaction within a distributed botanical garden environment in the university campus., This work was supported in part by the 2017 Predoctoral Research Grant supported by the Xunta de Galicia and the Research Projects under Grant TEC2017-85529-C03-3R and Grant RTI2018-095499-B-C31, in part by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España [MCIU/Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea (UE)], and in part by the European Union’s Horizon 2020 Research and Innovation Program (Stardust-Holistic and Integrated Urban Model for Smart Cities) under Grant 774094., This work was supported in part by the 2017 Predoctoral Research Grant supported by the Xunta de Galicia and the Research Projects under Grant TEC2017-85529-C03-3R and Grant RTI2018-095499-B-C31, in part by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España [MCIU/Agencia Estatal de Investigación (AEI)/Fondo Europeo de Desarrollo Regional (FEDER), Unión Europea (UE)], and in part by the European Union’s Horizon 2020 Research and Innovation Program (Stardust-Holistic and Integrated Urban Model for Smart Cities) under Grant 774094.

In the advent of becoming reality, the era of autonomous vehicles is closer than ever, and with it, the need for faster and reliable wireless connections. The propagation channel determines the performance limits of wireless communications, and with the aid of empirical measurements, channel modeling is the best approach to predict and recreate how signal propagation conditions may perform. To this end, many different approaches and techniques have been implemented, from specific applications to general models, considering the characteristics of the environment (geometry-based or non-geometry-based) as well as seeking high performance algorithms in order to achieve good balance between accuracy and computational cost. This paper provides an updated overview of propagation channel models for vehicular communications, beginning with some specific propagation characteristics of these complex heterogeneous environments in terms of diverse communication scenarios, different combinations of link types, antenna placement/diversity, potentially high Doppler shifts, or non-stationarity, among others. The presented channel models are classified in four categories: empirical, non-geometry-based stochastic, geometry-based stochastic, and deterministic models, following the classical approach. The features and key concepts of the different vehicular communications channel models are presented, from sub 6 GHz to millimeter wave (mmWave) frequency bands. The advantages and disadvantages of the main works in the area are discussed and compared in a comprehensive way, outlining their contributions. Finally, future critical challenges and research directions for modeling reliable vehicular communications are introduced, such as the effects of vegetation, pedestrians, common scatterers, micro-mobility or spherical wavefront, which in the context of the near future are presented as research opportunities., This work was supported in part by the School of Engineering and Sciences, Tecnológico de Monterrey, and in part by the Ministerio de Ciencia, Innovación y Universidades, Gobierno de España (MCIU/AEI/FEDER,UE), under Grant RTI2018-095499-B-C31 and Grant TEC2017-85529-C03-3R.

This paper presents the design and realization of a high-yield tuning-less waveguide diplexer and a high-gain lens horn antenna for 5G point-to-point fixed-beam communications at the frequency ranges of 71/76 GHz and 81/86 GHz (E-band). The diplexer is composed of two bandpass filters based on the combination of a low-pass filtering function and a high-pass structure. The diplexer provides very relaxed fabrication tolerances. A prototype has been fabricated and measured showing return loss better than 20 dB and attenuation levels higher than 60 dB. The insertion loss is better than 1 dB. A lens horn antenna which provides more than 38 dBi gain is utilized to provide high directivity at the same frequencies. The proposed sub-system combines the advantages of high-performance and simple mechanical assembly finding, it especially attractive for 5G applications due to the reduced fabrication cost., This work was supported by the Spanish Ministerio de
Ciencia, Innovación y Universidades–Agencia Estatal de
Investigación under Project TEC2017-85529-C3-2-R (AEI,
FEDER-EU).