Artículos (Electrónica y Electromagnetismo)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/10839

Examinar

Mostrando 1 - 20 de 557

An LC-tank based DCO for low-power high-speed applications using full-custom nMOS-type varactors
(Elsevier, 2024-11) Jiménez Fernández, Pablo; Rodríguez Pérez, Alberto; Prefasi, Enrique; Sierra, Francisco; Río Fernández, Rocío del; Guerra Vinuesa, Oscar; Electrónica y Electromagnetismo
LC-tank based Digital Controlled Oscillators (LC-DCOs) are widely used in digital assisted high-speed data communication systems due to their high quality factor (Q). Typically, LC-DCOs incorporate digital-controlled varactors for frequency control. The varactor structure significantly influences oscillator Q and phase noise performance. In this paper we propose using full-custom varactors built with digitally connected nMOS-type transistors to enhance the varactor Q by reducing its length. However, parasitic resistance from varactor array interconnection with the LC-tank can impact the overall oscillator performance. This paper presents a methodology to systematically include the proposed varactor array and its parasitic effects into LC-DCO design flow. Following the proposed method, an optimal combination of the inductor and varactor array can be accurately determined. As a proof of concept, we designed and manufactured a 23.5-GHz LC-DCO using 28-nm CMOS RF process. The oscillator exhibits a maximum phase noise of-90.1 dBc/Hz at 1-MHz offset with a power consumption of only 1.71 mW at 1-V supply.
Hermann Minkowski and the special theory of relativity
(Springer Nature, 2026) Pérez Izquierdo, Alberto Tomás; Ferreirós Domínguez, José Manuel; De Paz, María; Electrónica y Electromagnetismo; Filosofía y Lógica y Filosofía de la Ciencia; Ministerio de Ciencia e Innovación (MICIN). España
The special theory of relativity as we understand it today owes much to the figure of Hermann Minkowski. His are several fundamental concepts that appear in current textbooks. However, his contributions are not always recognized. Furthermore, some historians of science judge him with a certain severity, undermining the importance of his contributions. He himself provoked this attitude to some extent by arguing in his articles that mathematicians were in a better position than physicists to understand the new theory. This article is devoted to the figure of Minkowski in two aspects. On the one hand, we analyze the status of Minkowski’s original ideas in the special theory of relativity as currently studied and taught. We show that some textbooks of reference in physics do not properly acknowledge the contributions of Minkowski. On the other hand, we will illustrate with some examples how the figure of Minkowski is perceived by historians. We see that even today he has his supporters and detractors.
Dusty plasma actuators: ‘‘Powder-phobic’’ walls to mitigate clogging in granular flows
(Elsevier, 2026) Durán Olivencia, Francisco José; Pontiga Romero, Francisco de Paula; Moreno González, H.; Martín Alfonso, Manuel Antonio; Soria del Hoyo, Carlos; Valverde Millán, José Manuel; Física Aplicada II; Electrónica y Electromagnetismo
Clogging is a thornier problem for many production environments run by granular flows. The cure? Purging and cleaning the pipelines continuously. Although simple and certainly effective, such mechanical operations indicate that there is no pat answer to this challenge. Yet, stopping the line jeopardizes the reliability and predictability of production environments—two pivotal concerns for many industrial sectors, such as new energy systems based on granular media
NUFFT-Accelerated Spectral-Domain MoM With Asymmetric Rooftop Basis Functions for Multilayered Structures With Periodic Metallizations
(IEEE, 2024-01) Córcoles, Juan; Camacho Aguilar, Miguel; Rodríguez Boix, Rafael; Electrónica y Electromagnetismo; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; European Union (UE)
Abstract—In this paper we present an efficient implementation of the spectral domain Method of Moments (SD-MoM) for the analysis of periodic multilayered structures in the case where asymmetric rooftop basis functions defined in a non–uniform mesh are used. This mesh only needs to be generated in the bounding rectangle that encloses the electric or magnetic current to be discretized. The slowly convergent double infinite summations involved in the MoM matrix entries are computed by means of four two–dimensional Non–Uniform Fast Fourier Transforms (NUFFT-2D), and the singularities and quasi-singularities appearing in the spectral functions that are subjected to the NUFFT-2D are skipped by rearranging terms and introducing eight additional one-dimensional NUFFTs (NUFFT-1D). The code implementing the NUFFT-accelerated SD-MoM approach has been used to analyze cells of frequency selective surfaces (FSSs) and reflectarray antennas (RAs). We have found that the proposed NUFFT-accelerated SD-MoM can be up to three orders of magnitude faster than the brute-force SD-MoM (direct summation of the truncated series), and around two orders of magnitude faster than commercial software CST.
Exploiting Mirror Symmetry in the 2D MoM Analysis of the Scattering by Conducting Cylinders
(IEEE, 2024-09) Hidalgo Zamora, Francisco Javier; Rodríguez Boix, Rafael; Camacho Aguilar, Miguel; Corcoles, Juan; Electrónica y Electromagnetismo; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España
Abstract—In this paper the authors carry out a judicious application of the 2D Method of Moments (MoM) to the analysis of the scattering of plane waves by infinite conducting cylinders in the case where the cylinders show two orthogonal planes of mirror symmetry. In particular, the original MoM scattering problem is replaced by four new MoM scattering problems in which the two mirror symmetry planes behave as perfect electric conductors and/or perfect magnetic conductors. The current densities of the four new MoM problems only have to be obtained in one quarter of the cylinders cross-section, and therefore, the number of MoM matrix entries in each new problem is one sixteenth the number of MoM matrix entries in the original problem, which makes it possible to reduce the CPU time required for the solution of the original problem to roughly one fourth. Results are generated for cylinders where the cross section is a rectangle, a rhombus, an ellipse and an ogive, the one quarter CPU time reduction being confirmed in all cases.
A 91.4-dB SNDR 2-MS/s 18-bit SAR ADC With Enhanced Optimal-Combination-Algorithm-Based Calibration
(IEEE, 2026-04) Lyu, Yanjin; Li, Haoran; Wei, Haotian; Rosa Utrera, José Manuel de la; Hu, Yuanqui; Electrónica y Electromagnetismo; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España
This work presents a 2-MS/s 18-bit successive-approximation-register analog-to-digital converter (ADC). Acapacitor digital-to-analog converter (CDAC) and a resistor digital-to-analog converter (RDAC) are cascaded to avoid the linearity limitation caused by parasitic capacitors on the bridge capacitor between the CDAC and the RDAC. An optimal-combination-algorithm (OCA)-based calibration is adopted to improve the linearity of the CDAC and the matching between CDAC and the bridge capacitor, and a least significant bit (LSB)-side dynamic element matching (DEM) strategy is applied to further improve the CDAC linearity. As for the RDAC, this work makes it calibration free by combining the parallel R-unit and R-2R topology. Measurement results show that the proposed ADC can achieve 91.4-dB signal-to-noise and distortion ratio (SNDR), 12.0-parts-per-million (ppm) (3.1-LSB) integral non-linearity (INL), and 174.0-dB FOMS,SNDR (including the power consumed by the calibration logic), and the worst-case INL across 25 dies improves from 72.5ppm (19.0LSB) to 18.8ppm (4.9LSB) after the OCA-based calibration and theLSB-side DEM. To the best of the authors’ knowledge, this is the first high-precision (resolution ≥16 bit) data converter adopting OCA-based calibration.
Understanding the origin of a second mobility reversal in optoelectrically powered metallo-dielectric Janus particles
(Elsevier, 2025-05-15) Das, Sankha Shuvra; García Sánchez, Pablo; Ramos Reyes, Antonio; Yossifon, G.; Electrónica y Electromagnetismo; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; Israel Science Foundation
While previous studies indicated the mobility reversal of an electrically-powered metallo-dielectric Janus particle (JP) with increasing frequency, here we report an intriguing second mobility reversal observed in optoelectronically-driven JPs. In contrast to the commonly used setup with parallel ITO-coated glass substrates to induce a uniform electric field orthogonal to the velocity direction, this setup incorporates a thin photoconductive layer deposited on the bottom ITO-coated glass substrate. We have found that the reversal is associated with the asymmetry of the bottom substrate’s photoconductivity, localized underneath the JP, resulting from the self-shading effect of the metallic hemisphere under top optical illumination. Numerous control tests, including optical illumination from the bottom, along with numerical simulations, support this hypothesized mechanism.
The influence of frequency and gravity on the orientation of active metallo-dielectric Janus particles translating under a uniform applied alternating-current electric field
(Royal Society of Chemistry, 2024-05-28) Boymelgreen, Alicia; Kunti, Golak; García Sánchez, Pablo; Yossifon, Gilad; Electrónica y Electromagnetismo; Agencia Estatal de Investigación. España
Theoretical and numerical models of active Janus particles commonly assume that the metallo-dielectric interface is parallel to the driving applied electric field. However, our experimental observations indicate that the equilibrium angle of orientation of electrokinetically driven Janus particles varies as a function of the frequency and voltage of the applied electric field. Here, we quantify the variation of the orientation with respect to the electric field and demonstrate that the equilibrium position represents the interplay between gravitational, electrostatic and electrohydrodynamic torques. The latter two categories are functions of the applied field (frequency, voltage) as well as the height of the particle above the substrate. Maximum departure from the alignment with the electric field occurs at low frequencies characteristic of inducedcharge electrophoresis and at low voltages where gravity dominates the electrostatic and electrohydrodynamic torques. The departure of the interface from alignment with the electric field is shown to decrease particle mobility through comparison of freely suspended Janus particles subject only to electrical forcing and magnetized Janus particles in which magnetic torque is used to align the interface with the electric field. Consideration of the role of gravitational torque and particle-wall interactions could account for some discrepancies between theory, numerics and experiment in active matter systems.
Traveling-wave electrophoresis induced by coplanar microelectrode arrays
(Elsevier, 2026-01) Rodríguez Galán, Andrés; Pérez Izquierdo, Alberto Tomás; García Sánchez, Pablo; Ramos Reyes, Antonio; Electrónica y Electromagnetismo; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España; European Union (UE)
Glide Symmetry Can Be Key to Enhance the Performance of Periodicity-Based Microwave Bandstop Filters
(Institute of Electrical and Electronics Engineers (IEEE), 2025-06-25) Fernández Prieto, Armando; Mesa Ledesma, Francisco Luis; Martel Villagrán, Jesús; Quevedo-Teruel, Óscar; Medina Mena, Francisco; Electrónica y Electromagnetismo; Física Aplicada I; Física Aplicada II; Ministerio de Ciencia, Innovación y Universidades (MICIU). España
Higher-order symmetries are essential in physics and electromagnetism, providing insights into the fundamental principles that govern a great variety of physical phenomena. Beyond their theoretical importance, these symmetries bring practical advantages, simplifying complex calculations and enhancing the design and functionality of numerous technological applications. This article investigates the recent application of higher-order symmetries, particularly glide symmetry, in the design of planar microwave circuits, with a focus on common-mode rejection filters. By reviewing recent advancements and applications, we aim to underscore the potential of these advanced symmetries to significantly enhance the performance and versatility of micro-wave planar circuits, as well as to inspire further research and innovation within this field.
Analytical Modeling of the Dependence of the Open-Circuit Voltage With Temperature in CMOS Photodiodes
(Institute of Electrical and Electronics Engineers (IEEE), 2024-01-15) Fernández Peramo, Pablo; Leñero Bardallo, Juan Antonio; López Martínez, Juan Manuel; Rodríguez Vázquez, Ángel Benito; Electrónica y Electromagnetismo
The open-circuit voltage is a key parameter determining the harvesting capabilities of diodes operating in photovoltaic regimes. It depends on illumination and temperature which may limit the diode operation in some scenarios. Its dependence on illumination has already been reported. However, the latter has not been studied for diodes integrated into standard IC fabrication technologies. The model was validated with TCAD simulations within a wide operation range. In addition, the model was validated with experimental results. Diodes operating in photovoltaic mode were implemented in two different 180-nm fabrication technologies and characterized. Comparative results show the model qualifies to study how temperature variations can impact the performance of solar cells.
Addressing preprocessing for spectrum sensing using image processing
(Enero, 2025-01) Rojas Bustos, Andrés Bolivar; Dolecek, G. Jovanovic; Rosa Utrera, José Manuel de la; Electrónica y Electromagnetismo; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España
This paper presents a novel approach to preprocessing spectrograms for spectrum sensing (SS) from the image-processing perspective. Gaussian bilateral filtering, a common image-denoising technique, has been introduced to improve spectrograms in SS in high-noise environments. This approach is evaluated by simulating LTE and 5 G NR signal spectrograms across various signal-to-noise ratios (SNRs). An extensive review and comparison with recent spectrogram-based works for different applications demonstrated that the proposed approach does not depend on deep learning models to denoise spectrograms, showing a simpler yet effective strategy to address SS.
Concentration-polarization electroosmosis: Full numerical simulation and comparison with the thin double layer model
(AIP Publishing, 2026-06) Loucaides, Neophytos; García Sánchez, Pablo; Ramos Reyes, Antonio; Electrónica y Electromagnetismo; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Agencia Estatal de Investigación. España; European Union (UE); FQM253: Electrohidrodinámica y Medios Granulares Cohesivos
We present a comprehensive numerical study of concentration-polarization electroosmosis (CPEO) around a charged spherical particle subjected to an alternating current electric field. The analysis is based on the full solution of the coupled Poisson–Nernst–Planck and Stokes equations, allowing us to assess the validity of commonly used theoretical approximations. In particular, we compare the full numerical results with the macroscale electrokinetic model of Schnitzer and ariv (SY), which relies on the thin electrical double layer (EDL) assumption and is widely used to describe nonlinear electrokinetic phenomena. Our simulations are first validated against classical results for electrophoretic mobility, showing excellent agreement. We then investigate CPEO flows over a wide range of parameters, including electric field strength, frequency, zeta potential, and EDL thickness. For thin EDLs and sufficiently large zeta potentials, the SY model provides accurate predictions of both the flow structure and magnitude. However, significant deviations arise as the zeta potential decreases or as the EDL thickness increases. In the regime of thick EDLs, we observe qualitative changes in the flow, including a reversal of the quadrupolar pattern. Finally, we compare our numerical predictions with available experimental data, finding overall good agreement but also highlighting discrepancies at high electric field strengths, where the experimentally observed saturation of the flow is not captured by current models.
A Control-Bounded Quadrature Leapfrog ADC
(IEEE, 2024-02) Malmberg, H.; Feyling, F.; Rosa Utrera, José Manuel de la; Electrónica y Electromagnetismo; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España
In this paper, the design flexibility of the control-bounded analog-to-digital converter principle is demonstrated. A band-pass analog-to-digital converter is considered as an application and case study. We show how a low-pass control-bounded analog-to-digital converter can be translated into a band-pass version where the guaranteed stability, converter bandwidth, and signal-to-noise ratio are preserved while the center frequency for conversion can be positioned freely. The proposed converter is validated with behavioral simulations on several filter orders, center frequencies, and oversampling ratios. Additionally, we consider an op-amp circuit realization where the effects of first-order op-amp non-idealities are shown. Finally, robustness against component variations is demonstrated by Monte Carlo simulations.
Compressive Image Encoder Architecture for In-Sensor Feature-Space Sampling
(IEEE, 2026-01) Khan, Amir; Fernández Berni, Jorge; Carmona-Galán, Ricardo; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España
An architecture for the on-chip implementation of a compressive image encoder is presented. It is 100% compatible with standard CMOS image sensor architectures. It does not interfere with normal CMOS image sensor operation. No significant image degradation is expected. A stream of compressed vectors containing feature-space samples is provided in parallel with the full raw image data. The major technical challenges posed by the additional in-sensor circuitry are: introducing negligible disturbances on image capture and maintaining image resolution and quality. Concerning the compressive sampling measurement strategy, it is generated on-chip, without requiring storage or communication of the measurement matrix. A new pseudo-diagonal random ternary measurement matrix is proposed that generates compressed vectors that require only 6-bit ADC resolution to render accurate classification results. In addition, the proposed architecture is flexible to implement other measurement strategies. The proposed encoder architecture is implemented in a 110nm CMOS image sensor technology.
Design and Evaluation of Combined Hardware FIA and SCA Countermeasures for AES Cipher
(IEEE, 2024-08) Potestad Ordóñez, Francisco Eugenio; Tena Sánchez, Erica; Zuniga-Gonzalez, V.; Acosta Jiménez, Antonio José; Electrónica y Electromagnetismo; Tecnología Electrónica; Agencia Estatal de Investigación. España; Ministerio de Ciencia e Innovación (MICIN). España; Ministerio de Asuntos Económicos y Transformación Digital
The development of hardware countermeasures against hardware attacks has attracted the attention of the scientific community over the past two decades. Side-Channel Analysis (SCA) and Fault Injection Attacks (FIA) represent a significant risk to the security of cryptographic circuits. Combined countermeasures against these types of attack must be carefully designed if both protections are required in the same implementation without interfering with the other. In this paper, a combined proposal is presented to counteract the SCA and FIA attacks. SCA countermeasures are based on a low-entropy masking scheme, while the FIA countermeasure is based on a signature generator detection scheme. Both have been experimentally implemented in an AES cipher in FPGA. Experimental FIA attacks, first-order Correlation Power Analysis (CPA) attacks, and Test Vector Leakage Assessment (TVLA) tests have been carried out to evaluate the improvement in the security levels. The experimental results show that for an increase in area 28.77% and a frequency degradation of 4.05% with respect to the unprotected implementation, the protected Advanced Encryption Standard (AES) scheme shows great security metrics against FIA (99.87% fault coverage) and SCA attacks.
Low Entropy Masking Protection Scheme for Ascon Cipher to Counteract Side-Channel Attacks
(IEEE, 2025-11) Tena Sánchez, Erica; Potestad Ordóñez, Francisco Eugenio; Martín González, Miguel; Casado Galán, Alejandro; Acosta Jiménez, Antonio José; Electrónica y Electromagnetismo; Tecnología Electrónica; Ministerio para la Transformación Digital y de la Función Pública. España; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España
Since NIST selected the ASCON cipher as a finalist in the lightweight cipher competition for constrained environments in February 2023, the cipher has been a focus of researchers, industry and government. On the other hand, hardware-implemented cryptographic algorithms have had to deal with so-called Side-Channel Attacks (SCA) since their emergence in the late 1990s. Although the ASCON algorithm is relatively recent, SCA attacks that breach its security have been proposed in the literature. In this paper, we present a design methodology for a low entropy masking protection scheme in order to raise the ASCON algorithm’s security levels against SCA. To evaluate the proposed methodology, the ASCON’s permutation has been implemented in an Artix-7 Xilinx FPGA. The implemented design area overhead is 5.45% with respect to the unprotected implementation. A complete ASCON algorithm has been manufactured in a 65nm TSMC ASIC technology. To perform experimental SCA attacks on the ASCON ASIC, a PCB has been designed and manufactured to specifically perform power measurements on the ASIC core.
Hardware implementations, SCA/FIA attacks, and countermeasures for the ASCON AEAD cipher: A review
(IEEE, 2024-11) Martín González, Miguel; Tena Sánchez, Erica; Potestad Ordóñez, Francisco Eugenio; Acosta Jiménez, Antonio José; Electrónica y Electromagnetismo; Tecnología Electrónica; Agencia Estatal de Investigación. España; Ministerio de Ciencia e Innovación (MICIN). España
The design and implementation of lightweightoriented ciphers on hardware is an ever more important topic in Internet of Things (IoT) given the increasing abundance of devices needing secure communication in our modern society. ASCON was selected in 2023 as the new standard algorithm with authenticated encryption with associated data (AEAD) for lightweight applications by the National Institute of Standards and Technology (NIST). This paper offers a full bibliographic recollection of hardware implementations, attacks and countermeasures published about ASCON. From which ASCON has proven its simplicity allows many implementation design approaches to achieve great performance while staying lightweight. However, its unprotected implementations are not safe from hardware attacks, some of the published attacks even being able to dodge countermeasures. ASCON is expected to thrive as the new standard in its field, although further work is required in the development of secure implementations before it does so. Index Terms—Hardware security, ASCON AEAD, side-channel attacks, fault injection attacks, hardware countermeasures.
Numerical Analysis of Single Bubble Dynamics and Heat Transfer in Electric Field-Enhanced Nucleate Boiling
(Elsevier, 2024-09) Wang, Qi; Pérez Izquierdo, Alberto Tomás; Guan, Yifei; Wu, Jian; Electrónica y Electromagnetismo; National Natural Science Foundation of China; Fundamental Research Funds for Central Universities. China; Ministerio de Ciencia, Innovación y Universidades (MICIU). España; Ministerio de Economía y Competitividad (MINECO). España; Junta de Andalucía
This study investigated the dynamic characteristics and heat transfer performance of single bubble in nucleate boiling process under a uniform vertical electric field through numerical simulation. It detailed the dynamic behavior and characteristics of bubbles, focusing on the process from deformation to detachment, to reveal the influence of the electric field on nucleate boiling. By quantitatively comparing the effects of the electric field and gravity on bubble detachment period and system heat transfer performance, it was confirmed that under microgravity conditions, the electric field can be an effective means of enhancing nucleate boiling heat transfer. Furthermore, this work has also conducted three-dimensional (3D) numerical simulations and qualitatively and quantitatively compared it with the two-dimensional (2D) results. The research results indicate that although the 2D and 3D results are qualitatively similar, there are some quantitative differences. However, the 2D results still have reference value for analyzing the flow patterns and transition characteristics of the system. Quantitative results indicate that, for 2D results, the heat transfer enhancement ratio of the electric field is 2.07 at Bo=1.2. For BoE=500, the decrease in gravity acceleration leads to a 36% decrease in heat transfer. For 3D cases, the electric field only increases the heat transfer capacity by 40.1%, while the decrease in gravity acceleration leads to a 38.6% decrease in heat transfer capacity.
Electromagnetic Fault Injection Attack Methodology against AES Hardware Implementation
(IEEE, 2024-11) Casado Galán, Alejandro; Potestad Ordóñez, Francisco Eugenio; Acosta Jiménez, Antonio José; Tena Sánchez, Erica; Electrónica y Electromagnetismo; Tecnología Electrónica; Agencia Estatal de Investigación. España; Ministerio de Ciencia e Innovación (MICIN). España
Implementation attacks are a serious threat in the field of cryptography and the IoT. One particular type of implementation attack is Fault Injection Attacks (FIA). These attacks aim to modify the functionality of a certain cryptographic scheme by altering the value of certain bits or bytes inside the electronic circuit. Differential Fault Analysis (DFA) is a technique that exploits these introduced faults to retrieve sensible information about the cryptographic algorithm, like the secret key. There are several ways to perform an FIA, one of them is the electromagnetic FIA, which aims to insert faults in a circuit by generating an electromagnetic pulse (EMP) to induce Foucault currents inside the chip that affect the components inside. In this paper, a methodology to find the optimal locations to perform an electromagnetic FIA and test it in two circuits is presented: The first one is an implementation of a single S-Box of the Advanced Encryption Standard (AES) algorithm and the second one is a full implementation of the AES, both on an Artix-7 FPGA. Both examples show that inserting several types of faults that the DFA literature uses to break the cipher is possible.

Examinar

Envíos recientes