Jon Legarda

• PhD
• Researcher at University of Deusto

The main objective pursued by this survey is to debate the feasibility of a new distribution system in low voltage direct current (LVDC) microgrids and its impact on social development. To this end, this study provides valuable information for renewable energy planners and researchers, giving insights or solutions to reduce the transition gap betwe...

The popularity of renewable energy systems has contributed significantly in the last years to the utility of low voltage direct current microgrids. However, these systems come with new challenges. This survey focuses on introducing a state-of-the-art low voltage direct current distribution system and sheds light on the challenges that must be faced...

In the last few years, the Internet of Things, and other enabling technologies, have been progressively used for digitizing Food Supply Chains (FSC). These and other digitalization-enabling technologies are generating a massive amount of data with enormous potential to manage supply chains more efficiently and sustainably. Nevertheless, the intrica...

The development of e-textiles is fostering research in wireless energy transmission. This paper presents a purely textile 2.4 GHz WiFi band 2 × 2 rectenna array for RF energy harvesting. It utilizes the electromagnetically coupled microstrip patch antenna topology and a simple and precise construction method that provides a good performance repeata...

This communication presents an analytical framework that combines transmission line models for the design of electromagnetically coupled microstrip patch antennas for the 2.45 GHz industrial, scientific and medical band. It provides initial values for all dimensions of the antenna, with measured resonance frequency errors below 6%. The initial desi...

Piezoelectric energy harvesting is a promising technology that increases the autonomy of low power IoT devices in scenarios that are subjected to mechanical vibrations. This work shows the potential of this technology to power IoT devices with the energy that is harvested from vibrations occurred during air and road transportation. Adjusting the na...

A precise layer alignment is crucial to ensure performance repeatability of multilayer microstrip antennas. We introduce a novel lab-scale construction process for multilayer microstrip textile patch antennas that consists in combining an alignment method, based on laser-cut wood frames to perform accurate layer alignment, with a fast intra-layer a...

Fully textile smart wearables will be the result of the complete integration and miniaturization of electronics and textile materials. Off-body communications are key for connecting smart wearables with external devices, even for wireless power transfer or energy harvesting. They need to fulfill specific electromagnetic (EM) (impedance bandwidth (B...

Novel combinations of materials and construction techniques are key for the development of new textile antenna configurations for on-body applications. Stretchable, flexible and conformable features of textile antennas are one of the hot research topics nowadays. This work gives a step forward with new designs of purely textile spiral antennas with...

Mobile Wireless Sensor Networks (MWSN) are usually constrained in energy supply, which makes energy efficiency a key factor to extend the network lifetime. The management of the network topology has been widely used as a mechanism to enhance the lifetime of wireless sensor networks (WSN), and this work presents an alternative to this. Software Defi...

The Internet protocol suite is increasingly used on devices with constrained resources that operate as both clients and servers within the Internet of Things paradigm. However, these devices usually apply few-if any-security measures. Therefore, they are vulnerable to network attacks, particularly to denial of service attacks. The well-known SYN fl...

Device-to-Device (D2D) communication enables devices in proximity to establish a wireless direct link. However, these devices may be severely constrained in terms of memory, CPU, and processing resources. Hence, a D2D communication with a constrained device implies new challenges as it does not have the resources required to be secured with standar...

This work presents a new method that increases the energy conversion for linear vibration-based generators. Actually, these generators are chosen to have their resonance frequency equal to the ambient vibration frequency that provides the maximum power amplitude of the acceleration. Nevertheless, there is a resonance frequency at which the accelera...

Software-defined networking (SDN) is an emerging architecture that decouples the network control and data planes. This data plane abstraction provides a workaround to dynamically define and change the network topology and routing. Consequently, these features could drive a greater energy efficiency through the deployment of coordination algorithms...

This paper presents a PRIME subnetwork simulation model based on OMNeT++ that reproduces the behaviour of real networks. The developed simulation model uses the most common logical topology of a selected real network provided by a previous monitoring process. Thanks to the developed simulation model, different algorithms and utility applications ca...

New advances in biosensor and electronic technologies will merge in new health assistance paradigms strongly based on the remote biomonitoring. Biomedical circuit and systems have much to say on this, as for example the Central Venous Catheters (CVC). Central venous catheters are commonly used in clinical practice to improve a patient's quality of...

RFID is a key which enables technology for the Internet of Things paradigm, allowing the virtualization of the physical objects into the Internet. There are uncountable applications whereby these connected objects can be a breakthrough for new business models, and this work shows a good example of that. We present the RFID Presenter as the evolutio...

Central venous catheters (CVC) are commonly used in clinical practice to improve a patient's quality of life. Unfortunately, there is an intrinsic risk of acquiring an infection related to microbial biofilm formation inside the catheter lumen. It has been estimated that 80 % of all human bacterial infections are biofilm-associated. Additionally, 50...

New advances in biosensor and electronic technologies will merge in new health assistance paradigms strongly based on the remote Biomonitoring. Biomedical circuit and systems have much to say on this, as for example the central venous catheters (CVC). Central venous catheters are commonly used in clinical practice to improve a patient’s quality of...

New advances in biosensor and electronic technologies will merge in new health assistance paradigms strongly based on the remote Biomonitoring. Biomedical circuit and systems have much to say on this, as for example the central venous catheters (CVC). Central venous catheters are commonly used in clinical practice to improve a patient’s quality of...

Information and Communication Technologies (ICTs) continue to overcome many of the challenges related to wireless sensor monitoring, such as for example the design of smarter embedded processors, the improvement of the network architectures, the development of efficient communication protocols or the maximization of the life cycle autonomy. This wo...

In this work 32 surface Electromyography (sEMG) electrode locations and 41 signal-features are evaluated in order to achieve an accurate classification rate in a static-hand gesture classification task. A novel implementation of the minimal Redundancy Maximal Relevance (mRMR) Variable Selection algorithm is proposed with the aim of selecting the mo...

A model for fully integrated CMOS linear power amplifiers (PAs) is presented. The model predicts the performance of the CMOS PA in terms of power-added efficiency (PAE) and output power (POUT) with respect to the main design parameters, such as supply voltage, current consumption, gain and inductor quality factors (Qs). In order to demonstrate the...

This paper presents a microcontroller-based software voting process that complies with Safety Integrity Level-4 (SIL-4) requirements. The selected system architecture consists of a 2 out of 2 schema, in which one channel acts as Master and the other as Slave. Each redundant channel uses a microcontroller as central element. The present analysis dem...

Service Oriented Architectures offer an incomparable setting for the management and reuse ofservices. In the case of such big scaled architectures the ability to choose between thoseservices often gets blurry, because of the difficulty when trying to find the one which fitsbetter the actual needs, or even because its invocation process gets excessi...

Service Oriented Architectures offer an incomparable setting for the management and reuse of services, mixing different factors like software and services. The ability to choose between the services available often gets blurry, because of the difficulty when trying to find the best service that fits better the actual needs, or even because its invo...

The residential gateway (RG) is known as the connection box that provides multi-service access to the consumer networks. This work is focused on a multi-residential gateway (MRG) concept, which offers more service provisioning and management capabilities. The QoS support in this context is challenging, as new requirements must be fulfilled regardin...

One of the most restrictive linearity constraints to RF transmitter nonlinearity is the unwanted emission immediately outside the channel bandwidth, mostly known as adjacent channel leakage ratio (ACLR). In this paper, novel architecture design rules are presented for ACLR-level measurement in feedforward adaptive amplifiers. Both main and distorti...

A two-stage fully integrated power amplifier (PA) for the 802.11a standard is presented. The PA has been fabricated using UMC 0.18μm CMOS technology. Measurement results show a power gain of 21.1dB, a P1dB of 23.2dBm and a PSAT of 26.8dBm. The PAE is 29% and it is kept high by means of several integrated inductors. These inductors present low-DC re...

This letter analyses the low frequency noise performance in Gilbert-cell-based zero-IF mixers. Several issues for optimizing the flicker noise performance while keeping a good mixer performance in terms of gain, noise figure, and power consumption are introduced in a quantitative manner. A CMOS zero-IF mixer has been fabricated and measured. A flic...

A new concept of multi-residential gateway (MRG) capable of managing several residential units (e.g. homes, flats) simultaneously while offering new additional services is presented. Apart from the typical recommendations proposed for residential gateways, specific new requirements are introduced in order to overcome the multi-residential challenge...

The OSGi Framework offers a cooperative environment for the deployment and management of services for multidisciplinary software applications, achieving interoperability between systems. But even so, its service registry lack of non-syntactic information prohibits agents making this framework available for a wider range of applications. This paper...

In printed monopoles, the current distribution along the lower monopole sheet and upper groundplane edges can be made analogous to a transmission line distribution by an appropriate antenna feed design. Accordingly, the VSWR < 2 impedance bandwidth upper frequency limit can be estimated for staircase-profile printed 2D ultrawideband (UWB) monopoles...

From the current distribution on planar monopoles, transmission line modeling is applied to study this kind of antennas. Some reported techniques for broadband monopoles are approached by using this model from a qualitatively point of view. Conclusions are derived that help to match the monopoles over an ultrawide bandwidth regardless of whether th...

Nowadays, the medium access and network technologies for users who move across different access networks are already being developed, but the services level continues unexplored. In this work a new service delivery platform is going to be presented, which will support the new possibilities that the ubiquitous computing offers, especially in the res...

This book has been possible thanks to the research carried out throughout several years in the field of the linearization techniques applied to digital communication systems, particularly to those with high spectral efficient modulation techniques. It merges in the need of developing frequency efficient modulations with widespread codification tech...

As it has been noticed, actual and incipient communication systems require high linear amplification in their transmitters. Presently, high linear amplifiers bring with them reduced efficiency rates, so special circuit architectures have came out in recent years as alternative solutions.

Nothing is linear in the nature, obviously neither the components used in the radio frequency communication systems. Sometimes, those nonlinear effects are well used in order to carry out different essential features for the design of communication devices [1].

The Feedforward linearization technique was developed by H.S. Black in 1928 [28]. The most important characteristics of this technique in comparison with other common linearization techniques were the unconditional stability, the wideband signal linearization capability and the possibility to completely cancel the distortion components. However, th...

In the previous chapter a mathematical analysis has been done of the Feedforward linearization technique. The study has given the reasons that avoid a total cancellation of the distortion introduced by the power amplifier. Likewise, it has been notice the potential of the adjustment parameters to enhance the benefits of this linearization technique...

The performance of the output signal sensed in the characterization of Chapter 5 led to determine alternative adjustment methods to the basic one that try to achieve the desired trade-off between the linearity and efficiency rates of Feedforward amplifiers.

Despite the outstanding development achieved in the semiconductor technology in the course of the last decade, the solid state technology has not yet entirely replaced the vacuum technology in the field of power amplifiers.

The historical evolution of the radio-electric transmitters could be separated into five different eras: the arc and spark transmitters, the multipolar alternators, the thermoionic vacuum tubes, the discrete transistors, the integrated transistors.

An adaptive feedforward amplifier is implemented for a Universal Mobile Telecommunication System (UMTS) downlink channel (2110–2170 MHz). An exhaustive characterization of the space of solution has corroborated the feedforward theoretical behavior. As a result, an alternative adjustment method is proposed, called “maximum output,” which entails max...

This paper describes an up-converter circuit for a TV tuner chain that can be implemented in both analog and digital TV systems. The circuit is integrated into a low cost standard two metal layer 0.8μm SiGe technology and is composed with class AB Gilbert cell based active mixer and differential voltage-controlled oscillator (VCO). The use of a hig...

In this work an integrated 3.2GHz phase locked loop (PLL) with a self-biasing current source is presented. The circuit has been designed using a 3.3 V 0.18 mum CMOS technology. The synthesizer consumes 55 mW of which 20 mW is consumed by the VCO. The PLL has a bandwidth of 100 KHz and a phase noise of -111 dBc/Hz at 1 MHz offset frequency. The spur...

The new communication standards like UMTS increase the spectral efficiency but a high linearity is required. RF power amplifiers are basic components of all wireless transceivers used in the communication systems, and their efficiency directly influences on the complete communication system efficiency. It is proposed the implementation of a lineari...

This article describes the educational methodology related to the 'Software and Protocols Engineering: Software for Medical Equipment' subject, belonging to the Engineering School of the University of Navarra (TECNUN). The integral design of embedded systems is successfully overcome through the use of techniques from Software Engineering and System...