Margarita Marrero-Martin

University of Las Palmas de Gran Canaria | ULPGC · Instituto Universitario de Microelectrónica Aplicada (IUMA)

Today, mechanical tracking systems are becoming increasingly compact, enabling a new range of civil and military applications. These include aerial laser scanning, for which Risley prisms are used. In Risley systems, the so-called inverse problem, which focuses on obtaining the angles of the prisms for a given target coordinate, has not yet been so...

Today, mechanical tracking systems have been downsized to allow them to be used in the field of airborne laser communications and in the military domain. Risley systems are used for this purpose, which work by directing a beam of light to a given target point, this procedure is commonly known as the inverse problem. In this paper, an analytical met...

Several causes make brain cancer identification a challenging task for neurosurgeons during the surgical procedure. The surgeons’ naked eye sometimes is not enough to accurately delineate the brain tumor location and extension due to its diffuse nature that infiltrates in the surrounding healthy tissue. For this reason, a support system that provid...

Hyperspectral (HS) imaging presents itself as a non-contact, non-ionizing and non-invasive technique, proven to be suitable for medical diagnosis. However, the volume of information contained in these images makes difficult providing the surgeon with information about the boundaries in real-time. To that end, High-Performance-Computing (HPC) platfo...

The precise delineation of brain cancer is a crucial task during surgery. There are several techniques employed during surgical procedures to guide neurosurgeons in the tumor resection. However, hyperspectral imaging (HSI) is a promising non-invasive and non-ionizing imaging technique that could improve and complement the currently used methods. Th...

In this paper the N-well resistance in doughnut-shaped PN varactors, with the cathode connected to an N+ buried layer, has been modelled. The proposed expression for the N-well resistance, numerically validated, is based on the device geometry and overlapping of adjacent basic cells, and adequately reproduces its applied reverse bias voltage depend...

The objective of this work is to study the possibility of implementing SOI rectifiers for UWB RFIDs with undoped Double Gate MOSFETs (DG-MOSFETs). For that purpose we use two commercial TCAD tools, Sentaurus Device (created by Synopsys) and ADS (created by Agilent), where in a large signal circuit model derived for the transistors is implemented wi...

The objective of this work is to study the possibility of implementing SOI rectennas for UWB RFIDs, with undoped Double Gate MOSFETs (DG-MOSFETs). For that purpose we use two commercial TCAD tools: Sentaurus Device (created by Synopsys), and ADS (created by Agilent) where in a large signal circuit model derived for the transistors is implemented wi...

The objective of this work is to study the possibility of implementing SOI rectifiers for UWB RFIDs with undoped Double Gate MOSFETs (DG-MOSFETs). For that purpose we use two commercial TCAD tools, Sentaurus Device (created by Synopsys) and ADS (created by Agilent), wherein a large signal circuit model derived for the transistors is implemented wit...

This article presents a wide range inductance–capacitance voltage controlled oscillator (VCO) with a unit cells-based varactor. The unit cell represents the minimum possible integrated varactor based on p–n junction diodes, where N diffusions are central rectangles, surrounded by doughnut shaped P diffusions, with their respective contacts. The var...

Variable capacitors, the varactors, are key components in many types of radiofrequency circuits and thus high quality varactors are essential to achieve high quality factors in these devices. This work presents results of a study on the variation of tuning range and quality factor when varying the depth and separation of N+ diffusions in a PN junct...

In this work varactors based on pn-junction have been connected in parallel with accumulation mode MOS ones, in order to increase the final capacitance without losing the particular characteristics. So, three double varactors have been designed, fabricated and on-wafer measured. Results demonstrate that the combination of these varactors improve th...

This paper compares different circuit models describing the performance of integrated varactors, which are designed, manufactured, measured and simulated with a 0.35 µm silicon standard technology. Three models are presented, named: simple, capacitive-inductive and physical. Their differences consist on the circuit elements used, capacitances, indu...

This paper is devoted to analyzing varactors based on PN junction cells in order to obtain a capacitance model for radiofrequency (RF) applications. A cell is the minimum structure that can be considered a varactor, including all necessary layers and connections. Then, a specific capacitance for a RF integrated circuit is obtained overlapping all n...

In this work, varactors based on PN junction cells have been studied in order to obtain a capacitance model for radiofrequency applications. These cells are unit cells: the minimum structure that can be considered a varactor, including all necessary layers and connections. Then, a specific capacitance for a radiofrequency integrated circuit (RFIC)...

Integrated varactors are key elements in radio frequency integrated circuits. In this paper, several structures of varactors, based on p-n junction cells, are considered. A capacitance model is required to use these structures in a CAD environment. We have developed a model which considers area and perimeter capacitances of adjacent unit cells so a...

In this work, four different structures based on PN junction are studied. These structures are based on changing the geometry of the p+ diffusion. The designed and fabricated devices will be used like integrated varactors in radiofrequency applications. The measures have been made at frequencies since 500 MHz to 10 GHz, and the influence that diffu...

This paper addresses practical considerations for the implementation of algorithms developed to increase the image resolution from a video sequence by using techniques known in the specialized literature as super-resolution (SR). In order to achieve a low-cost implementation, the algorithms have been mapped onto a previously developed video encoder...

Advances in fabrication and design technologies have contributed to integrate a complete system on a chip. A system-on-chip (SoC) is generally composed of a microprocessor core, on-clip memory and one or more specific coprocessors IPs. One of the major drawbacks of this approach is the differences in the interfaces that each virtual component (VC)...

At 0.25, 0.18 um processes and beyond important process variations occur not only from one fab to another among batches. Moreover as we approach the realm of deep-submicron design, process variations even across a single die are predicted to become a major source of spread. Reduced signal levels, noise margins and timing windows are all contributin...

Durante años, la verificación de placas de circuitos impresos (PCBs) se realizaba directamente sobre los prototipos diseñados, sin una fase previa de simulación. Por lo que el éxito del diseño realizado dependía en mayor medida de la experiencia del diseñador y en muchos casos, pequeños o incluso, grandes errores hacía necesario el diseño de otra P...