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This paper proposes a distributed intelligent secondary control (SC) approach based on brain emotional learning-based intelligent controller (BELBIC) for power electronic-based ac microgrid (MG). The BELBIC controller is able to learn quick-auto and handle model complexity, non-linearity, and uncertainty of the MG. The proposed controller is fully model-free, indicating that the voltage amplitude and frequency deviations are regulated without previous knowledge of the system model and parameters. This approach ensures low steady-state variations with higher bandwidth and maintains accurate power-sharing of the droop mechanism. Furthermore, primary control is realized with a robust finite control set-model predictive control (FCS-MPC) in the inner level to increase the system frequency bandwidth and a droop control in the outer level to regulate the power-sharing among the distributed generations. Finally, experimental tests obtained from a hardware-in-the-loop testbed validate the proposed control strategy for different cases.

Publisher Copyright: Author In this paper, we compare in a new way the energy efficiencies of modulations that have been popular in ultra-low power (ULP) transmitters. The comparison considers how the choice of modulation affects the combined energy consumed per bit (EPB) by the carrier synthesizer and power amplifier (PA). The comparison includes on-off keying (OOK), binary phase-shift keying (BPSK), binary frequency-shift keying (BFSK), pulse-position modulation (PPM) and differential PPM (DPPM). The results suggest that using OOK, BPSK or BFSK can consume tens to hundreds of percents more energy per bit compared to PPM and DPPM. Furthermore, a new energy efficiency figure of merit (FOM) is derived for transmitters. It accounts for consumed power, output power, data rate, signal bandwidth and signal-to-noise ratio required by the utilized modulation. The FOM can be applied to various types of transmitters with numerous modulations. We also present a sub-100 W DPPM transmitter (TX) and a 3.2- W 2-axis gesture sensor interface, implemented in 0.18 m CMOS. The TX operates in the 433-MHz band, uses pulse shaping for improved spectrum and achieves a FOM of 189.7 dBJ/bit. The estimated uplink range is up to 1 kilometer

As the bandwidth of radio signals increases significantly over the evolution of communication systems, the analysis bandwidth of many current instruments becomes insufficient. In this article, we study analysis bandwidth extension using the so-called band stitching. Specifically, we propose a two-step delay estimation method, which combines the cross correlation and an additional refining step to resolve the timing impairment between different sampling branches in postprocessing. We verify the method with a sequential measurement setup, using vector signal analyzers (VSAs). The result shows the necessity of conducting the refining step for getting a more accurate delay estimate to successfully recover the original wideband signal. Besides, a good agreement is found between the stitched data and the reference data in terms of the waveforms and error vector magnitude (EVM), which shows the effectiveness and robustness of the proposed calibration method in practice.

This article presents a broadband sub-terahertz (THz) power amplifier (PA) with a low-loss four-way power combiner. The proposed power combiner consists of an improved zero-degree combiner (ZDC) and a three-conductor Marchand balun simultaneously achieving broadband matching and power combining. The proposed three-conductor Marchand balun adopts a dual- $LC$ tank technique by merging two resonators, and it can be equivalent to a transformer-based multi-resonating network. The power distribution is realized by one input power splitter generating two pairs of differential signals and two parallel 1-to-2 active power splitters. This hybrid distribution driving network further enhances efficiency and power gain. Based on these improvements, a high-output-power sub-THz PA with superior efficiency has been fabricated in the 130-nm SiGe bipolar complementary metal oxide silicon field effect transistor (BiCMOS) technology. The three-stage PA achieves a peak power gain of 16.4 dB, 3-dB small-signal gain bandwidth of 52 GHz from 211 to 263 GHz, a measured maximum saturated output power of 14.7 dBm at 224 GHz, and a peak power-added efficiency (PAE) of 3.13% at 220 GHz. The folded input splitter and extremely compact power combining methodology lead to a core area of 770 $\mu$ m $\times$ 280 $\mu$ m.

Audio bandwidth extension aims to expand the spectrum of narrow-band audio signals. Although this topic has been broadly studied during recent years, the particular problem of extending the bandwidth of historical music recordings remains an open challenge. This paper proposes BEHM-GAN, a model based on generative adversarial networks, as a practical solution to this problem. The proposed method works with the complex spectrogram representation of audio and, thanks to a dedicated regularization strategy, can effectively extend the bandwidth of out-of-distribution real historical recordings. The BEHM-GAN is designed to be applied as a second step after denoising the recording to suppress any additive disturbances, such as clicks and background noise. We train and evaluate the method using solo piano classical music. The proposed method outperforms the compared baselines in both objective and subjective experiments. The results of a formal blind listening test show that BEHM-GAN significantly increases the perceptual sound quality in early-20th-century gramophone recordings. For several items, there is a substantial improvement in the mean opinion score after enhancing historical recordings with the proposed bandwidth-extension algorithm. This study represents a relevant step toward data-driven music restoration in real-world scenarios., Comment: Accepted at IEEE Transactions on Audio, Speech, and Language Processing

A compact asymmetric coplanar strip (ACS)-fed monopole antenna is presented, which operates within the Bluetooth and UWB frequency bands with the capability to simultaneously reject the lower WLAN interfering band. The antenna consists of an inverted right triangle patch monopole loaded by open-ended L-shaped slits not only to produce the additional 2.4 GHz passband to the UWB design but also to achieve stopband characteristics around 5.2 GHz. The conceptual equivalent circuit model as well as characteristic mode analyses are carried out in the design evolution process. The proposed antenna has an overall size of only 20 mm x 10 mm, having the smallest area among the so far developed designs, which can be easily integrated within any wireless gadgets. A prototype is fabricated and measured to validate the design, demonstrating the predicted behavior fairly achieved by full-wave analysis. The antenna -10 dB operating bandwidth ranges from 2.38 to 2.42 GHz and from 3.35 to 11 GHz while rejecting from 4.69 to 5.2 GHz. Unlike the unwanted stopband, where the radiation characteristics are adequately deteriorated, the proposed antenna fairly provides stable omni-directional radiation patterns in the H-plane, and has an average efficiency (gain) of 87.3% (2.6 dBi) in the desired passband. As far as the antenna transient behavior is concerned, an adequate measured (simulated) system fidelity factor of 0.7 (0.68) is achieved for the transmission of impulse-type UWB signals in the face-to-face configuration.

The growing interest in quantum technologies, from fundamental physics experiments to quantum computing, demands for extremely performing electronics only adding the minimum amount of noise admitted by quantum mechanics to the input signal (i.e. quantum-limited electronics). Superconducting microwave amplifiers, due to their dissipationless nature, exhibit outstanding performances in terms of noise (quantum limited), and gain. However, bandwidth and saturation power still show space for substantial improvement. Within the DARTWARS* collaboration, we are developing state-of-the-art microwave superconducting amplifiers based on Josephson junction arrays and on distributed kinetic inductance transmission lines. Here we report the realization of a setup for the characterization of the performances of Josephson Traveling-Wave Parametric Amplifiers (JTWPA) at a temperature of 300 mK. Although in the final experimental setup these amplifiers will operate at a base temperature of about 20 mK, their characterization at 300 mK allows to evidence the main aspects of their performances, but the ultimate noise level. This represents a quick and relatively inexpensive way to test these superconductive devices that can be of help to improve their design and fabrication. IEEE

Big data analytics platforms have played a critical role in the unprecedented success of data-driven applications. However, real-time and streaming data applications, and recent legislation, e.g., GDPR in Europe, have posed constraints on exchanging and analyzing data, especially personal data, across geographic regions. To address such constraints data has to be processed and analyzed in-situ and aggregated results have to be exchanged among the different sites for further processing. This introduces additional network delays due to the geographic distribution of the sites and potentially affecting the performance of analytics platforms that are designed to operate in datacenters with low network delays. In this paper, we show that the three most popular big data analytics systems (Apache Storm, Apache Spark, and Apache Flink) fail to tolerate round-trip times more than 30 milliseconds even when the input data rate is low. The execution time of distributed big data analytics tasks degrades substantially after this threshold, and some of the systems are more sensitive than others. A closer examination and understanding of the design of these systems show that there is no winner in all wide-area settings. However, we show that it is possible to improve the performance of all these popular big data analytics systems significantly amid even transcontinental delays (where inter-node delay is more than 30 milliseconds) and achieve performance comparable to this within a datacenter for the same load.

In this paper, we provide, for the first time, a comprehensive understanding of LoRa waveform theory in order to quantify its orthogonality. We present LoRa waveform expressions in continuous and discrete time domains, and analyze measures of orthogonality between different LoRa spreading factors (SFs) through cross-correlation functions. The crosscorrelation functions are analytically expressed in a general form and they account for diverse configuration parameters (bandwidth, SF, etc.) and different cases of signal displacements (time delay shift, frequency shift, etc.). We quantify their mean and maximum in all time domains. We highlight the impact of the temporal displacement and different bandwidths. The general result is that LoRa modulation is non-orthogonal. Firstly, we observe that for same bandwidths the largest maximum crosscorrelation happens for same SF and is equal to 100% due to same symbols; whereas for different bandwidths, the largest maximum cross-correlation is no longer observed at the same SF. Secondly, the maximum cross-correlation is less than 26% between different SFs, is higher for closer SFs and decreases as the difference between SFs increases. After downchirping, the maximum crosscorrelation increases and the mean decreases compared to those before downchirping. Moreover, the maximum cross-correlation is insignificantly impacted by the temporal delay which makes it valid to adopt for the performance analysis of both synchronous and asynchronous systems. Finally, we analyze by simulation the bit error probability statistics for different bandwidth ratios and highlight their correlated behaviour with the insights obtained from the maximum cross-correlation expressions.

This paper presents a novel concept for spatial diversity using plastic optical fibre (POF)-based luminaire transmission for in-home networks. We show the feasibility of an optical transmission system using POFs, acting as optical front-haul, for realizing a high capacity wireless bidirectional link aided by a spatial diversity scheme allowing user mobility around the access points. The light coming out of the 1 mm core diameter step-index POF is highly divergent and, therefore, for each POF-end an optical lens is placed to adjust the size of wireless cells, in order to allow user's mobility or to adjust the number of users served by the access points. Thus, the access points are completely passive, hence no electrical powering is needed, resulting in low maintenance. In addition, active components such as light sources and detectors can be located remotely from the access points and they are connected to each other by POFs. Futhermore, we performed optical wireless experiments with an eye-safe visible light laser and therefore our wireless link is limited to 1.2 m and 45 cm diameter of coverage areas. We obtained multi-Gbps for downlink and uplink and compared the link performance using discrete multitone, pulse amplitude modulation, and Nyquist sub-carrier modulation.

This article presents a novel and cost-effective vector network analyzer (VNA)-based phase-compensated channel sounder operating in the frequency range of 10-50 GHz using radio-over-fiber (RoF) techniques, which can support multilink/channel long-range phase-coherent measurements. The optical cable enables long-range channel measurements with a dynamic range of 115.7 dB at 30 GHz (for the back-to-back connection). The phase compensation scheme is utilized for stabilizing the inherent phase variations introduced by the optical fiber of the channel sounder to enable its application in multichannel/antenna measurements. A novel optical delay line and combiner scheme is proposed and implemented to separate the signals, thereby saving the port resource on the VNA for multilink/channel measurements. The proposed channel sounder is validated in back-to-back measurements under two optical cable conditions, i.e., with the presence of thermal changes and mechanical stress. The phase change could be maintained within 3° at 10-30 GHz and 7° in 30-50 GHz compared to the over 80° phase variation introduced by the cable effects at 10-50 GHz, demonstrating the robustness and effectiveness of the developed channel sounder in practice. With the proposed optical delay line and combiner scheme, multiple channels can be measured simultaneously with minimal VNA ports, significantly reducing the measurement cost and time for multilink channel measurements. Two multilink indoor channel measurements are conducted and analyzed using a virtual uniform rectangular array (URA) at 28-GHz bands. The results demonstrate the capability of the proposed channel sounder to perform high-fidelity long-range ultrawideband multilink channel measurements.

This paper presents a digitally programmable bi-directional 7-bit passive phase shifter in a 65 nm CMOS technology. The core of this passive vector-synthesized phase shifter is a hybrid quadrature generator (HQG), an interstage matching network, and a passive vector modulator (PVM). This work proposes a high coupling-factor-based quadrature generator design methodology and demonstrates it with a compact vertical transformer. The interstage matching network between HQG and PVM is proposed to release the bandwidth bottleneck and achieve a 34% fractional frequency bandwidth. Two 6-bit X-type attenuators in the I and Q path form a high-resolution 12-bit controlling word. In 32-40 GHz, this 7-bit 360 ∘ phase shifter achieves a measured 2.8 ∘ step with 0.45-1.6 ∘ RMS phase error and 0.2-0.36 dB RMS magnitude error. With the broadband technique, its 3-dB bandwidth reaches 30.2-42.7 GHz with a 2.8 ∘ RMS phase error. Its in-band 1-dB compression point is 10.2 dBm. With the proposed compact HQG and PVM, this mm-wave passive phase shifter only occupies 220×630 μ m 2 and has no power consumption.

International audience; We present the design and experimental validation of wideband dual-circularly-polarized (dual-CP) reflect-arrays (RAs) based on dual-functional-layered unit cells with independent control of circular polarizations. The proposed dual-CP RA cells comprise a circular polarization selective surface (CPSS) on the top based on a bandwidth-enhanced dual-meandered Pierrot structure that implements polarization selection of CP waves and a reflective half-wave plate (HWP) on the bottom. The dual-CP phase delay of the RA cells relies on the Berry-phase (BP) dictated by the rotation of the CPSS and HWP elements for achieving reflective beamforming of CP waves of opposite handedness. The diffractive properties of an infinite periodic gradient array of the dual-CP RA cells in a triangular lattice are investigated, which numerically verifies the dual-CP anomalous reflection capability. Two proof-of-concept RAs operating at X-band are designed, fabricated, and characterized. By replacing only the bottom functional layer of the RA, symmetrical and asymmetrically distributed dual-CP beams can be obtained. A measured peak gain of higher than 23.5 dBic is achieved, with a joint bandwidth of 11% for an axial ratio < 2 dB and a gain variation < 1 dB. The improved bandwidth performance, high-resolution BP compensation, and printed manufacturing process without using any metallic cavities make the demonstrated CPSS-based dual-CP RAs promising candidates for wireless and satellite communications.

For wireless communications using linear large-scale antenna arrays, we define a receiving coordinate system and parameterization strategy to facilitate the study of the impact of three-dimensional position and rotation of the arrays on the achievable spatial degrees of freedom (DoF) in line-of-sight (LOS) channels. An analytical framework based on spatial bandwidth analysis is developed, under which three elementary problems corresponding to three basic orthogonal receiving directions are investigated. For each of them, accurate, simple, and interpretable closed-form approximations for the achievable spatial DoF are derived, and the spatial region where a sufficient amount of spatial DoF is expected available is determined. The expressions can easily be integrated into large-scale system-level simulations. Some interesting and surprising observations are made from simulation studies based on the analytical results. For instance, the spatial bandwidth is shown to be approximately constant in almost the entire spatial multiplexing region. Moreover, in significant parts of this region, the optimal receive array orientation is not parallel with the transmitting array., 18 pages, 11 figures, submitted to IEEE Journal on Selected Areas in Communications

In this work, a parametric up-converter amplifier is introduced as a wideband impedance-matching network. Chu’s limit restricts the minimum Q-factor of unloaded small antennas. However, the practical bandwidth (BW) of small antennas is defined by their loaded Q-factor. By connecting a small antenna to an amplifier with a real input impedance that is several times greater than the radiation resistance of the antenna, we propose increasing the return loss, which leads to a reduction in the loaded Q-factor and an increase in the BW. In addition, a parametric amplifier is used because, in comparison with transistor amplifiers, it offers low-noise characteristics. The gain of the low-noise parametric amplifier compensates for the loss due to the imposed mismatch. Our simulation result shows BW improvements up to 32 times can be accomplished by trading 2 dB of noise figure (NF), compared to the 15 dB suggested by Chu’s limit for a lossy antenna. Accepted version

none 12 si In this paper we present D.A.V.I.D.E. (Development for an Added Value Infrastructure Designed in Europe), an innovative and energy efficient High Performance Computing cluster designed by E4 Computer Engineering for PRACE (Partnership for Advanced Computing in Europe). D.A.V.I.D.E. is built using best-in-class components (IBM’s POWER8-NVLink CPUs, NVIDIA TESLA P100 GPUs, Mellanox InfiniBand EDR 100 Gb/s networking) plus custom hardware and an innovative system middleware software. D.A.V.I.D.E. features (i) a dedicated power monitor interface, built around the BeagleBone Black Board that allows high frequency sampling directly from the power backplane and scalable integration with the internal node telemetry and system level power management software; (ii) a custom-built chassis, based on OpenRack form factor, and liquid cooling that allows the system to be used in modern, energy efficient, datacenter; (iii) software components designed for enabling fine grain power monitoring, power management (i.e. power capping and energy aware job scheduling) and application power profiling, based on dedicated machine learning components. Software APIs are offered to developers and users to tune the computing node performance and power consumption around on the application requirements. The first pilot system that we will deploy at the beginning of 2017, will demonstrate key HPC applications from different fields ported and optimized for this innovative platform. open Abu Ahmad, Wissam; Bartolini, Andrea; Beneventi, Francesco; Benini, Luca; Borghesi, Andrea; Cicala, Marco; Forestieri, Privato; Gianfreda, Cosimo; Gregori, Daniele; Libri, Antonio; Spiga, Filippo; Tinti, Simone Abu Ahmad, Wissam; Bartolini, Andrea; Beneventi, Francesco; Benini, Luca; Borghesi, Andrea; Cicala, Marco; Forestieri, Privato; Gianfreda, Cosimo; Gregori, Daniele; Libri, Antonio; Spiga, Filippo; Tinti, Simone

The increasing demand and use of internet networks at PT. Satria Jaya Prima to access a website-based sales system, the more user demand for problems that occur on user devices such as unstable internet networks. Currently the use of internet network at PT. Satria Jaya Prima has not been efficient because there is no balanced bandwidth regulation, thus making the internet network capacity usage gap and making the internet network unstable. Based on these problems, research is needed that can be applied to overcome these problems, namely managing bandwidth using Mikrotik. In the network, a device is needed that can manage the existing internet network. This device is called Mikrotik RouterBoard. Routers that will be used in the internet network of PT. Satria Jaya Prima runs with Mikrotik OS for bandwidth and user management and manages the existing internet network according to the internet needs of internet network users. In this study, Mikrotik is configured using Winbox using the Simple Queue Peer Connection Queue (PCQ) method, with bandwidth management and users using the Mikrotik Router, the internet network connection will be smoother, because the existing bandwidth is allocated to each user based on the bandwidth needs needed by each internet network user

IPv4 address space is about to reach its limit and could collapse. To correct this event, many propose that existing networks should make the definitive migration to IPv6, taking as a reference that this protocol will allow a larger IP address space, providing new opportunities and correcting the existing problems in the protocol of the previous version. However, due to the increased overhead in IPv6 and its interaction with edge routers and operating systems that host this communication protocol, network performance problems can obviously occur. This article is based on a quantitative research using a method that allows analyzing the performance of networks based on IPv6 with IPSec using simulation with GNS3, with this tool compares results with three typical scenarios of implementation in relation to the original topology of this work, Its evaluation determines the difference in performance between scenarios when traffic is generated from one network to another and a scenario with better stability and performance is obtained from among them using an experimental methodology, with which we will be able to verify that its counterpart scenario with the use of tunnels is more optimal in relation to the one proposed in this research, taking into consideration that the metrics analyzed are bandwidth, latency and jitter., El espacio de direcciones IPv4 está a punto de llegar a su límite y podría colapsar, para corregir este evento muchos proponen que las redes existentes deberán realizar la migración definitiva a IPv6, tomando como referencia que este protocolo permitirá un mayor espacio de direcciones IP, brindando nuevas oportunidades y corrigiendo los problemas existentes en el protocolo de la versión anterior. Sin embargo, debido al aumento de la sobrecarga en IPv6 y su interacción con routers de borde y sistemas operativos que alojan este protocolo de comunicación, se pueden ocasionar evidentemente problemas de rendimiento en la red. El presente artículo se basa en una investigación cuantitativa utilizando un método que permite analizar el rendimiento de redes basadas en IPv6 con IPSec haciendo uso de la simulación con GNS3, con dicha herramienta compara resultados con tres escenarios típicos de implementación en relación a la topología original del presente trabajo, su evaluación determina la diferencia de rendimiento entre escenarios cuando se genera tráfico de una red a otra y se obtiene de entre ellos el un escenario con mejor estabilidad y rendimiento utilizando una metodología experimental, con lo que logramos constatar que su escenario homólogo con utilización de túneles en más óptimo en relación al propuesto en esta investigación, tomando en consideración que las métricas analizadas son ancho de banda, latencia y jitter.

This paper presents the design and analysis of a Microstrip Patch Antenna (MPA) array with Defected Ground Structure (DGS) for Internet of Things (IoT) applications. Given the ever-growing demand for efficient wireless communication systems, the proposed antenna design serves to enhance the performance characteristics of IoT devices, particularly in terms of bandwidth and gain. Using Ansys HFSS for simulation, an array of MPAs has been designed, featuring a copper patch and feed on a FR4-Epoxy substrate. The key advantages of the proposed design include its compactness, high efficiency, and low production cost. Additionally, DGS has been integrated to increase bandwidth and gain, effectively overcoming the traditional limitations of MPAs. The antenna exhibits an optimal performance at a resonant frequency of 3 GHz. This novel antenna design is suitable for various IoT applications, such as mobile satellite communication, GPS, telemetry, telemedicine, and more.

Publisher Copyright: IEEE This brief introduces new methodologies to design microstrip line crossovers on a high-speed interconnection circuit. The crossover is based on a simple square patch, which employs TM100 and TM001 to achieve mode orthogonality so that two sets of intersecting signals can transmit along microstrip lines with a high isolation. Compared with rectangular waveguide crossovers that employ high modes, namely TE102 and TE201, it shows advantages like a smaller size and easier manufacturing. Then, the relevant techniques for performance improvement, including radiation suppression and bandwidth widening, are studied for practical circuit designs. Finally, based on the sub-element technique, the study designs a controllable frequency response for two intersecting signals and miniaturization of patch based crossovers. Two examples are implemented, manufactured and measured to justify the validity of the sub-element technology. In addition, the design steps of this method are simplified compared with relying on full-wavesimulations entirely.

This work presents a 28/38 GHz dual-band power amplifier (PA) for fifth-generation (5G) communication. In this work, a T-topology-matching network is proposed at the output for its dual-band operation and low insertion loss. Also, a modified dual-LC tank-matching method is proposed for the input and interstage part due to its wideband performance and large-impedance transformation capability. This modified dual-LC tank boosts the transformation ratio to 30 at the interstage matching without trading bandwidth for the 28/38 GHz operation. Furthermore, circular inductors are applied to the matching networks for low insertion loss. This design is fabricated in a 0.25-μm SiGe:C BiCMOS technology with a core area of 300 × 770 μm2. In combination with the proposed methods, this PA achieves 28/38 GHz dual-band operation with high power-added efficiency (PAE). At 28 GHz, the measured peak power-added efficiency (PAEpeak) is 25%, the saturated output power (Psat) is 18.8 dBm, and 1-dB compressed power (P1 dB) is 17.8 dBm. At 38 GHz, those are 17.5%, 17 dBm, and 15.8 dBm, respectively.

This article proposes a grid-forming based decoupling approach, which effectively mitigates the dynamic interactions between active and reactive power, especially suitable for system stabilization in ultrastrong grids with short-circuit ratio over 30. The physical coupling behaviors are first revealed by analytical studies, where two potential resonances, respectively, located in 40-50 Hz and 0-10 Hz are discovered with mathematical proofs. Based on the results, the decoupling controller is then designed with transfer function approximation for practical usage. The control method not only suppresses the couplings but also cancels two pairs of conjugate poles through decoupling paths. Thanks to the cancellation, the stability margin is remarkably increased in stiff grids, and therefore, a significant bandwidth boost on the power synchronization control can be realized if desired. The experimental results are finally performed to verify the proposed decoupling method.

This article presents a 16-MHz RC frequency reference implemented in a standard 180-nm CMOS process. It consists of a frequency-locked loop (FLL) in which the output frequency of a digitally controlled oscillator (DCO) is locked to the frequency-phase characteristic of a Wien bridge RC filter. Since it is made from on-chip resistors and capacitors, the filter's characteristic is temperature dependent. To compensate for this, the control signal of the DCO is derived by digitizing the filter's output phase and combining it with the digital output of a Wheatstone bridge temperature sensor. After a two-point trim, this digital temperature compensation scheme achieves an inaccuracy of ±90 ppm from -45 °C to 85 °C. The frequency reference draws 220 $\mu \text{A}$ from a 1.8-V supply, with a supply sensitivity of 0.12%/V and a 320-ppb Allan Deviation floor for a 10-s stride.

Ultralow-noise microwave amplification and detection play a central role in different applications, going from fundamental physics experiments to the deployment of quantum technologies. In many applications the necessity of reading multiple detectors, or cavities or qubits, calls for large bandwidth amplifiers with the lowest possible noise. Current technologies are based on High Electron Mobility Transistors and Josephson Parametric Amplifiers. Both have limitations, the former in terms of the minimum noise, the latter in terms of bandwidth. Superconducting Traveling Wave Parametric Amplifiers (TWPAs) have the potential of offering quantum limited noise and large bandwidth. These amplifiers are based on the parametric amplification of microwaves traveling along a transmission line with embedded nonlinear elements. We are developing superconducting TWPAs based both on Josephson junction arrays (Traveling Wave Josephson Parametric mplifiers) and on nonlinear kinetic inductance (Dispersion Engineered Traveling Wave Kinetic Inductance Amplifiers). Our goal is to achieve large bandwidth (in the 5 to 10 GHz range), large gain (more than 20 dB), large saturation power (more than -50 dBm), and near quantum limited noise (noise temperature less than 600 mK). Current achievements in the design and development of the high performance TWPAs are here reported and discussed, together with current limitations and possible future developments.

Multi-band (MB) technology arises as a suitable solution to increase capacity within future 6G networks, while efficiently utilizing the already deployed optical fiber infrastructure. Indeed, the adoption of MB sliceable bandwidth/bit rate variable transceivers (S-BVTs) based on multi carrier modulation (MCM) enables transmission within multiple bands beyond C-band, providing sustainable capacity growth and hyper-scalability. Different slices/bands can be suitably activated in a pay-as-you grow approach according to the network demand and requirements. Additionally, the proposed MB S-BVT architecture also enables disaggregation and programmability by the adoption of an open software-defined networking (SDN) paradigm. A proof of concept of the proposed MB S-BVT is numerically and experimentally evaluated. Specifically, the transmission of 25 GHz signals/slices working at C-, L- and S-band is considered without any filtering and amplification stages. About 70 Gb/s capacity per slice/band is achieved in B2B configuration. The data rate decreases after 50.47 km, enabling maximum capacities per slice of 26.2 Gb/s (C-band) and 21 Gb/s (L- and S-bands). Additionally, the proposed MB S-BVT can be envisioned to serve different classes of services/applications over different network segments, prepared to support MB technology, thanks to the exploitation of differently performing slices/bands. © 1983-2012 IEEE.

High control bandwidth is usually restricted in a photoelectric tracking system (PTS) based on a Charge-Couple Device(CCD) with time delay, which hinders a good tracking performance. Generally, a model-based delay-compensation controller called Smith predictor (SP) can help increase the controller gain to promote the bandwidth by separating delay from the control loop. However, the performance promotion is insufficient because the delay still stays in the forward channel which causes errors between output and input. And the increase of the controller gain is still limited due to the effect of model mismatch on stability. In this paper, to solve the problems, a delay-compound-compensation control (DCCC) based on improved SP by trajectory prediction and velocity feedforward is proposed. The additional trajectory prediction is used to further eliminate the effect of delay existing in the forward channel. The additional velocity feedforward is used to further reform the transfer characteristics limited by the controller gain. A Kalman filter-based design method of trajectory prediction is presented and the optimal design principle of feedback and feedforward controllers is given in the face of model mismatch. Experiments demonstrate that the DCCC is valid and could greatly promote the tracking performance in the low frequency.

In three-phase three-wire (3P3W) voltage-source converter (VSC) systems, utilization of filter inductors with deep saturation characteristics is often advantageous due to the improved size, cost, and efficiency. However, with the use of conventional synchronous frame current control methods, the inductor saturation results in significant dynamic performance loss and poor steady-state current waveform quality. This article proposes an inverse dynamic model-based compensation (IDMBC) method to overcome these performance issues. For this purpose, two-phase exact modeling of the 3P3W VSC control system is obtained. Based on the modeling, the inverse system dynamic model of the nonlinear system is obtained and employed such that the nonlinear plant is converted to a virtual linear inductor system for linear current regulators to perform satisfactorily. Further, to control phase currents in the synchronous frame, a two-phase coordinate transformation is proposed. The IDMBC method is tested via dynamic command response and waveform quality simulations and experiments that employ saturable inductors reaching down from full inductance at zero current to 1/9th inductance at full current. The results obtained demonstrate the suitability of the method for 3P3W VSCs employing saturable inductors. Publisher's Version

Phased arrays, commonly used in IEEE 802.11ad and 5G radios, are capable of focusing radio frequency signals in a specific direction or a spatial region. Beamforming achieves such directional or spatial concentration of signals and enables phased array-based radios to achieve high data rates. Designing beams for millimeter wave and terahertz communication using massive phased arrays, however, is challenging due to hardware constraints and the wide bandwidth in these systems. For example, beams which are optimal at the center frequency may perform poor in wideband communication systems where the radio frequencies differ substantially from the center frequency. The poor performance in such systems is due to differences in the optimal beamformers corresponding to distinct radio frequencies within the wide bandwidth. Such a mismatch leads to a misfocus effect in near-field systems and the beam squint effect in far-field systems. In this paper, we investigate the misfocus effect and propose InFocus, a low complexity technique to construct beams that are well suited for massive wideband phased arrays. The beams are constructed using a carefully designed frequency modulated waveform in the spatial dimension. InFocus mitigates beam misfocus and beam squint when applied to near-field and far-field systems.

High-level synthesis (HLS) is an increasingly popular method for generating hardware from a description written in a software language like C/C++. Traditionally, HLS tools have operated on sequential code, however in recent years there has been a drive to synthesise multi-threaded code. In this context, a major challenge facing HLS tools is how to automatically partition memory among parallel threads to fully exploit the bandwidth available on an FPGA device and minimise memory contention. Existing partitioning approaches require inefficient arbitration circuitry to serialise accesses to each bank because they make conservative assumptions about which threads might access which memory banks. In this article, we design a static analysis that can prove certain memory banks are only accessed by certain threads, and use this analysis to simplify or even remove the arbiters while preserving correctness. We show how this analysis can be implemented using the Microsoft Boogie verifier on top of satisfiability modulo theories (SMT) solver, and propose a tool named EASY using automatic formal verification. Our work supports arbitrary input code with any irregular memory access patterns and indirect array addressing forms. We implement our approach in LLVM and integrate it into the LegUp HLS tool. For a set of typical application benchmarks our results have shown that EASY can achieve 0.13×(avg. 0.43×) of area and 1.64×(avg. 1.28×) of performance compared to the baseline, with little additional compilation time relative to the long time in hardware synthesis.

The demand for internet service has always been on the rise especially with the advent of new technological devices and the current information age. In this study, the data showing internet bandwidth consumed daily for staff and students of the University of Benin was considered based on maximum demand. The internet bandwidth data was chronologically harvested for 370 days and used to predict internet bandwidth demand. Data was examined for stationary and model fitness using autocorrelation function (ACF) and partial autocorrelation function (PACF) tests. Several ARIMA models were considered for predicting the demand as well as an outlier detection approach and the data was split in two for training and testing the model. The training data consisted of 200 data points while the testing had 160 data points. The result obtained showed that there were 13 outliers present in the data and the seasonal ARIMA(0,0,2)(0,1,1)7 was most suited with the stationary R2 of 0.959, R2 value of 0.957, root mean square error (RMSE) of value of 15.296, mean absolute error(MAE) of 10.852 and the normalized Bayesian information criterion (NBIC) score of 5.731.

This study proposed the dimensions of 55 mm × 34 mm × 1 mm for wearable antenna; the copper Y-slot patch and copper partial ground are attached to a felt substrate. The partial ground has the higher impact in antenna gain enhancement compared with the full ground, making it the most suitable candidate for wearable applications and suitable for embedding in fabrics for use in medical applications. In addition, the proposed antenna design combined a fabric–metal barrier operated at 2.4 GHz 65.4% with a low specific absorption rate (SAR) of 0.01 watts per kilogramme (W/kg) and 0.006 W/kg per 10 g and a gain of 6.48 dBi. The proposed antenna has an omnidirectional radiation pattern. The two-layer barrier is designed to achieve high electromagnetic (EM) absorption and reduce the antenna’s absorption coefficient (SAR) for safe use in applications involving human activities. Simulation and measurement results on the arm and the head of the human body indicated that the antenna has excellent performance. In addition, the measurement results agreed well with the simulation results, making the proposed wearable antenna reliable for medical and 5G applications.

International audience; This paper represents a new MIMO antenna design with compact diversity resonators for future smartphone applications. Four pairs of diversity monopoles with CPW feeding have been deployed at the mainboard’s corners to create an 8×8 MIMO configuration. The array designed takes up a comparatively compact space. The design’s antenna radiators have been etched onto the layer that shares the same surface as the PCB ground. The MIMO antenna is designed for 3.6 GHz of sub-6 GHz spectrum and offers a 3.4-3.8 GHz bandwidth. Overall, the planned MIMO array can achieve optimal results and meet the demand for future 5G portable devices such as smartphones.

The ability to measure emotional states in daily life using mobile devices has led to a surge of exciting new research on the temporal evolution of emotions. However, much of the potential of these data still remains untapped. In this paper, we re-analyze emotion measurements from seven openly available Experience Sampling Methodology (ESM) studies with a total of 835 individuals to systematically investigate the modality (unimodal, bimodal, more than two modes) and skewness of within-person emotion measurements. We show that both multimodality and skewness are highly prevalent. In addition, we quantify the heterogeneity across items, individuals, and measurement designs. Our analysis reveals that multimodality is more likely in studies using an analogue slider scale than in studies using a Likert scale; negatively valenced items are consistently more skewed than positive valenced items; and longer time series show a higher degree of modality in positive and a higher skew in negative items. We end by discussing the implications of our results for theorizing, measurement, and time series modeling.

High-speed wireless communication devices need antennas to operate at multiple frequencies with high gain. The need for such antennas is increasing day by day. The proposed metamaterial superstrate antenna gives a high gain and multiband performance, which is required in high-speed wireless communication devices. The designed antenna is also applicable for C- and X-band communication devices. The structure consists of a simple patch and multiple split-ring resonator metamaterials on the superstrate region. The performance optimization is achieved by adjusting the feed position, varying the height of the superstrate layer and changing the thickness of metamaterial rings. The proposed design is analyzed for 4 GHz to 12 GHz. The performance analysis regarding the reflection coefficient, directivity, gain and electric field is observed. FR4 is used as a dielectric material that makes the design low-cost. The proposed design represents a minimum reflection coefficient response of −49 dB, a bandwidth of 490 MHz, a maximum electric field of 1.29 × 104 v/m, good directivity and a broader radiation pattern. The comparison between the simulated and the measured results is incorporated in the manuscript. A comparison of the presented design with other articles is included to check the novelty of the design. The proposed method helps to target applications such as WiFi, Earth observation and microwave links.

Jurnal Penelitian ini memberikan informasi tentang hasil analisis terkait paket manajemen Bandwidth yang efektif dan efisien. Penelitian ini dapat digunakan oleh masyarakat serta pengguna internet dalam proses pembelajaran jaringan dengan menggunakan metode Simple Queue dan Quality Of Service untuk menghasilkan kasimpulan akhir. Metode penelitian dalam penelitian ini terbagi atas beberapa tahapan yaitu tahapan identifikasi masalah, tahapan pengumpulan data, perencangan pembuatan dan pengujian sistem. Lokasi pada penelitian ini bertempat PT Adhiyaksa Daya Sentosa berada di Cikarang, Bekasi. Sampel penelitian menggunakan beberapa aplikasi pendukung, sehingga bisa mendapatkan bukti data. Penelitian dilakukan dengan aplikasi winbox untuk konfigurasi, aplikasi wireshark untuk mendapatkan data paket internet dan web browser. Berdasarkan hasil pengolahan data, dapat menarik kesfimpulan bahwa penelitian dengan menggunakan aplikasi pendukung dan menggunakan metode Simple Queue dan Quality Of Service dapat mengetahui jumlah paket dan bisa manajemen Bandwidth. Serta bisa mengetahui bagian rinci dari kecepatan dan kelambatan dalam penggunaan metode tersebut. Dari penelitian ini dapat memberikan manfaat berupa informasi terkait aplikasi dan penggunaan yang efektif dan efisien yang bisa digunakan pada proses pembelajaran atau proses kerja dalam lingkup internet.

Possible dynamic interactions among multiple dc microgrid power converters that are connected to a common dc bus can lead to performance degradation or even stability issues in some control loops. Thus, in order to maintain a desired dynamic behavior when operating conditions or system parameters are changing, an interesting approach is to adopt autotuning for the controller parameters. In general, existing autotuning methods are based on the evaluation of the stability specifications (e.g., the crossover frequency and the phase margin) and the adaptation of the controller to ensure the specified dynamic properties. However, the desired bandwidth and phase margin may not be achievable due to parameter changes, unexpected additional delays, or unmodeled dynamics in the feedback loop. This article addresses the infeasibility issue by adding an external control loop on top of the autotuning unit. This external loop adjusts the reference crossover frequency until the phase margin specification is fulfilled. As a result, the proposed scheme is capable of tracking the highest bandwidth at which the reference phase margin is achievable, i.e., the maximum allowable bandwidth. The proposed method is applied to a dc microgrid prototype, and the simulation and experimental results are discussed.

A computational grid needs to be cost-effective and highly reliable. It must have the ability to transfer maximum amount of data for end-to-end delivery. Many research works on computational grids conclude with a binary state of operation. Although some research reveals that, the grids operate with multiple states of connections and operations, they are silent about the mentioned constraints. Since there are multi-state operations, the reliability depends on the load, bandwidth and cost. This paper proposes a Genetic Algorithm (GA) based approach for optimization of reliability of computational grid with desired reliability under cost and bandwidth constraints. The method is well explained through illustration and its implementation on some Grid networks. The efficient encoding, cross-over, mutation and selection operation of the proposed scheme ensures the fast convergence to the optimal solution. On comparison, the proposed method is observed to be more efficient than the existing ones.

In this paper, we propose a deep reinforcement learning (DRL)-based algorithm to generate policies of Baseband Function (BBF) placement and routing. In order to explore the performance of the proposed algorithm in practical systems, the online scenario with the completely random requests is used in the simulation considering C-RAN and NG-RAN architectures. Besides, an Integer Linear Programming (ILP) model is formulated to generate the optimal solution as the benchmark. The simulation results show that DRL-based algorithm converges in a short time, and its performance closes to the optimal benchmark obtained by ILP in terms of latency and bandwidth for the online scenarios. In addition, the performance of the generated policies based on DRL is compared with a classic heuristic algorithm, i.e., first-fit algorithm. The performance of DRL-based algorithm is superior to the first-fit algorithm from above two perspectives. The fast convergence and the near-optimal performance prove that the DRL-based algorithm is a promising approach for the BBF placement and routing of RAN in 5G and Beyond.

In event-based sensing, many sensors independently and asynchronously emit events when there is a change in their input. Event-based sensing can present significant improvements in power efficiency when compared to traditional sampling, because (1) the output is a stream of events where the important information lies in the timing of the events, and (2) the sensor can easily be controlled to output information only when interesting activity occurs at the input. Moreover, event-based sampling can often provide better resolution than standard uniform sampling. Not only does this occur because individual event-based sensors have higher temporal resolution, it also occurs because the asynchrony of events allows for less redundant and more informative encoding. We would like to explain how such curious results come about. To do so, we use ideal time encoding machines as a proxy for event-based sensors. We explore time encoding of signals with low rank structure, and apply the resulting theory to video. We then see how the asynchronous firing times of the time encoding machines allow for better reconstruction than in the standard sampling case, if we have a high spatial density of time encoding machines that fire less frequently., Comment: 12 pages, 8 figures

International audience; We propose a novel Mean-Shift method for data clustering, called Robust Mean-Shift (RMS). A new update equation for point iterates is proposed, mixing the ones of the standard Mean-Shift (MS) and the Blurring Mean-Shift (BMS). Despite its simplicity, the proposed method has not been studied so far. RMS can be set up in both a kernel-based and a nearest-neighbor (NN)-based fashion. Since the update rule of RMS is closer to BMS, the convergence of point iterates is conjectured based on the Chen's BMS convergence theorem. Experimental results on synthetic and real datasets show that RMS in several cases outperforms MS and BMS in the clustering task. In addition, RMS exhibits larger attraction basins than MS and BMS for identical parametrization; consequently, its kernel variant requires a lower aperture of the kernel function, and its NN variant a lower number of nearest neighbors compared to MS or BMS, to achieve optimal clustering results. In addition, the NN version of RMS does not need to specify a convergence threshold to stop the iterations, contrarily to the NN-BMS algorithm.

This work was supported in part by IHS Kurumsal Teknoloji A.S., and in part by the Tuerkiye Bilimsel ve Teknik Arastirma Kurumu(TUBITAK) under Grant 115E389 User Provided Network (UPN) is a promising solution for sharing the limited network resources by utilizing user capabilities as a part of the communication infrastructure. In UPNs, it is an important problem to decide how to share the resources among multiple clients in decentralized manner. Motivated by this problem, we introduce a new class of games termed distribution games that can be used to distribute efficiently and fairly the bandwidth capacity among users. We show that every distribution game has at least one pure strategy Nash equilibrium (NE) and any best response dynamics always converges to such an equilibrium. We consider social welfare functions that are weighted sums of bandwidths allocated to clients. We present tight upper bounds for the price of anarchy and price of stability of these games provided that they satisfy some reasonable assumptions. We define two specific practical instances of distribution games that fit these assumptions. We conduct experiments on one of these instances and demonstrate that in most of the settings the social welfare obtained by the best response dynamics is very close to the optimum. Simulations show that this game also leads to a fair distribution of the bandwidth. IHS Kurumsal Teknoloji A.Ş Türkiye Bilimsel ve Teknolojik Araştırma Kurumu (TÜBİTAK) Publisher's Version Q2 WOS:000892934100001

The base station-mobile device communication traffic has dramatically increased recently due to mobile data, which in turn heavily overloaded the underlying infrastructure. To decrease Base Station (BS) interaction, intra-cell communication between local devices, known as Device-to-Device, is utilized for distributed data caching. Nevertheless, due to the continuous departure of existing nodes and the arrival of newcomers, the missing cached data may lead to permanent data loss. In this study, we propose and analyze a class of Low-Density Parity Check (LDPC) codes for distributed data caching in cellular networks. Contrary to traditional distributed storage, a novel repair algorithm for LDPC codes is proposed which is designed to exploit the minimal direct BS communication. To assess the versatility of LDPC codes and establish performance comparisons to classic coding techniques, novel theoretical and experimental evaluations are derived. Essentially, the theoretical/numerical results for repair bandwidth cost in presence of BS are presented in a distributed caching setting. Accordingly, when the gap between the cost of downloading a symbol from BS and from other local network nodes is not dramatically high, we demonstrate that LDPC codes can be considered as a viable fault-tolerance alternative in cellular systems with caching capabilities for both low and high code rates.

The aim of adaptive HTTP streaming technology is preserving the best possible video streaming quality for viewers in heterogeneous network conditions. This can be achieved by making multiple quality versions of the video available. Switching between versions during playback should be imperceptible and fluent. The decision about quality-level switching is typically based on network capacity estimation and buffer occupancy, which predict the risk of stalling. Since quality-level switching and stalling are directly evident to the user, they are often classified as influence factors of quality of experience (QoE). In this paper, we observe different network capacity estimators and buffer behavior in limited network conditions and study how the estimators predict QoE. The challenges of variable bitrate (VBR)-encoded video are considered. We also propose two new estimators to predict QoE. One compares segment fetch time to segment playback time, while the other explores the difference of throughput and average download rate. As segment duration may influence HTTP adaptive streaming (HAS) playback in unstable conditions, the findings are tested with four segment lengths. Moreover, streaming quality is analyzed in a testbed using two popular web players to reveal possible effects of the players’ features. peerReviewed

Antennas on-chip are a particular type of radiating elements valued for their small footprint. They are most commonly integrated in circuit boards to electromagnetically interface free space, which is necessary for wireless communications. Antennas on-chip radiate and receive electromagnetic (EM) energy as any conventional antennas, but what distinguishes them is their miniaturized size. This means they can be integrated inside electronic devices. Although on-chip antennas have a limited range, they are suitable for cell phones, tablet computers, headsets, global positioning system (GPS) devices, and WiFi and WLAN routers. Typically, on-chip antennas are handicapped by narrow bandwidth (less than 10%) and low radiation efficiency. This survey provides an overview of recent techniques and technologies investigated in the literature, to implement high performance on-chip antennas for millimeter-waves (mmWave) and terahertz (THz) integrated-circuit (IC) applications. The technologies discussed here include metamaterial (MTM), metasurface (MTS), and substrate integrated waveguides (SIW). The antenna designs described here are implemented on various substrate layers such as Silicon, Graphene, Polyimide, and GaAs to facilitate integration on ICs. Some of the antennas described here employ innovative excitation mechanisms, for example comprising open-circuited microstrip-line that is electromagnetically coupled to radiating elements through narrow dielectric slots. This excitation mechanism is shown to suppress surface wave propagation and reduce substrate loss. Other techniques described like SIW are shown to significantly attenuate surface waves and minimise loss. Radiation elements based on the MTM and MTS inspired technologies are shown to extend the effective aperture of the antenna without compromising the antenna’s form factor. Moreover, the on-chip antennas designed using the above technologies exhibit significantly improved impedance match, bandwidth, gain and radiation efficiency compared to previously used technologies. These features make such antennas a prime candidate for mmWave and THz on-chip integration. This review provides a thorough reference source for specialist antenna designers. This work was supported in part by the Universidad Carlos III de Madrid and the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant 801538, in part by the Icelandic Centre for Research (RANNIS) under Grant 206606, and in part by the National Science Centre of Poland under Grant 2018/31/B/ST7/02369.

A broadband linearly polarized reflectarray antenna is designed by modifying a typically narrowband square patch unit element with cross-loop slot (CLS). Due to the introduction of the CLS, the unit patch element becomes multi-resonant and miniaturized. Besides, the outer length and width of the CLS are one-to-one related to the length of the patch. As a result, more than 480° phase range with quite good linearity is achieved. In addition, the phase ranges are almost parallel to each other from 22.5–26.5 GHz, which signifies its broadband property. Using such $36\times 36$ CLS patches in a square aperture of 180 mm $\times180$ mm size, an offset-fed reflectarray is constructed for an off-broadside radiation pattern. A prototype has been fabricated to experimentally validate the numerical results obtained using CST full-wave simulations. The measurement results exhibit a broad 1-dB gain bandwidth of 17.6% (22.44–26.78 GHz) and a peak gain of 32.2 dBi with an aperture efficiency of 60.6%. Moreover, both the cross-pol and side-lobe levels (SLLs) remain more than 40 dB and 21 dB, respectively, below the peak co-pol level throughout the 1-dB gain bandwidth. The proposed reflectarray can be used as a CubeSat antenna for K-band inter-satellite links (ISL).

DC microgrids (DCMGs) integrate and coordinate various DC distribution generation units including various renewable energy sources and battery storage systems, and have been used in satellites, the International Space Station, telecom power stations, computer power supplies, electric aircraft, and electric ships. However, the presence of constant power loads (CPLs) can cause instability in DCMGs. Thus, this paper reviews the stabilization techniques that can resolve instability caused by CPLs, as well as various parameters of CPLs, such as bandwidth, and the frequency of the CPLs that can stabilize the DCMGs. It also discusses recent trends and future work in finding stability limits using the parameters of CPLs. It should be useful for directing research towards appropriate mathematical and experimental approaches for the stability of DCMGs with CPLs.

Developments in making customer-oriented services (customer oriented) are numerous so that they are increasingly spoiling customers. Likewise with the very rapid development of the Start Up world in Indonesia, so that many large companies are interested in developing Start Ups under their supervision, such as CV Fasnet Media collaborating customer oriented and Start Up services. Collaboration is carried out such as in building a system to prevent interruptions in products and subscriptions. In the course of the New interruption and subscription prevention system requires a website to monitor the operation of the system. CV Fasnet Media is still experiencing bandwidth management problems, therefore a special system is needed where workers can more easily manage data -data l to support the administration of activities that are effective, efficient and can provide easily accessible information facilities. In monitoring the website, it is intended for the responsible party (Team Leader) in monitoring activation by technicians who use a disturbance prevention system and new subscriptions. In monitoring the website also displays potential fault points around the area, then can manage data technicians and customers registered in the intrusion prevention system. This monitoring makes it easier for Team Leaders because they can manage technicians and see potential interference points visually provided on the web-based Monitoring System website.