Towards a cyber physical system for personalised and automatic OSA treatment

Obstructive sleep apnea (OSA) is a breathing disorder that takes place in the course of the sleep and is produced by a complete or a partial obstruction of the upper airway that manifests itself as frequent breathing stops and starts during the sleep. The real-time evaluation of whether or not a patient is undergoing OSA episode is a very important task in medicine in many scenarios, as for example for making instantaneous pressure adjustments that should take place when Automatic Positive Airway Pressure (APAP) devices are used during the treatment of OSA. In this paper the design of a possible Cyber Physical System (CPS) suited to real-time monitoring of OSA is described, and its software architecture and possible hardware sensing components are detailed. It should be emphasized here that this paper does not deal with a full CPS, rather with a software part of it under a set of assumptions on the environment. The paper also reports some preliminary experiments about the cognitive and learning capabilities of the designed CPS involving its use on a publicly available sleep apnea database

Proposal of a health care network based on big data analytics for PDs

Health care networks for Parkinson's disease (PD) already exist and have been already proposed in the literature, but most of them are not able to analyse the vast volume of data generated from medical examinations and collected and organised in a pre-defined manner. In this work, the authors propose a novel health care network based on big data analytics for PD. The main goal of the proposed architecture is to support clinicians in the objective assessment of the typical PD motor issues and alterations. The proposed health care network has the ability to retrieve a vast volume of acquired heterogeneous data from a Data warehouse and train an ensemble SVM to classify and rate the motor severity of a PD patient. Once the network is trained, it will be able to analyse the data collected during motor examinations of a PD patient and generate a diagnostic report on the basis of the previously acquired knowledge. Such a diagnostic report represents a tool both to monitor the follow up of the disease for each patient and give robust advice about the severity of the disease to clinicians

Хвилеводно-планарні смугові фільтри із широкою смугою загородження

The article presents the results of the development of a novel procedure for the direct synthesis of bandpass E-plane evanescent mode filters. Unlike previously developed synthesis procedures the proposed new and quick synthesis technique makes it possible to obtain the dimensions of all elements of the filter topology, which either do not require further time-consuming optimization, or optimization is reduced to re-application of the proposed technique with specially changed performance requirements. The developed technique was adequate in the development of the proposed E-plane filters, built on segments of the antipodal finline with the significant overlap of its ridges in the evanescent mode rectangular waveguide. Under this conditions the reduction of resonators relative to half the wavelength reaches 80 %. Proposed E-plane implementation of the evanescent mode rectangular waveguide filter allows significantly expanding the bandwidth, increase the attenuation introduced in it and at the same time ensure the repeatability of the characteristics of the filters without any action to adjust them. The effectiveness of the proposed approach to the implementation of the filter and its calculation was demonstrated in the development and experimental study of a 21 GHz filter, which in terms of parameters (loss of about 1 dB, stopband up to the fourth harmonic of the central frequency of passband) meets high requirements for electrical characteristics and cost. It is shown that the developed method of synthesis of such filters remains relevant in the synthesis of filters with a relative bandpass width of up to 40 %.В статье приведены результаты разработки процедуры прямого синтеза полоснопропускающих фильтров, построенных на планарных металло-диэлектрических структурах, расположенных в запредельном прямоугольном волноводе. Разработанная методика синтеза позволяет получить размеры всех элементов топологии фильтра, которые или не нуждаются в дальнейшей трудоемкой оптимизации, или оптимизация сводится к повторному применению предложенной методики с искусственно измененными требованиями к характеристике, основанными на данных об отклонении характеристики синтезированного фильтра от требуемой. Разработанная методика оказалась адекватной при разработке предложенных волноводно-планарных фильтров, построенных на отрезках антиподальной волноводно-щелевой линии в запредельном прямоугольном волноводе. При значительном перекрытии ее гребней сокращение резонаторов относительно половины длины волны достигает 80\%. Указанная волноводно-планарная реализация фильтра на запредельном прямоугольном волноводе позволяет значительно расширить полосу частот заграждения, увеличить вносимое в ней затухания и одновременно обеспечить повторяемость характеристик фильтров без каких-либо действий по их настройке. Эффективность предложенного подхода к реализации фильтра и его расчету продемонстрирована на примере разработки фильтра диапазона 21 ГГц, который по совокупности параметров (потери порядка 1 дБ, ширина полосы заграждения до четвертой гармоники центральной частоты полосы пропускания) соответствует высоким требованиям к электрическим характеристикам и технологичности. Показано, что разработанная методика синтеза подобных фильтров остается актуальной при синтезе фильтров с относительной шириной полосы частот пропускания до 40 %.В статті наведені результати розробки процедури прямого синтезу смугопропускаючих фільтрів, побудованих на планарних метало-діелектричних структурах, розташованих в позамежовому прямокутному хвилеводі. Розроблена методика синтезу дозволить отримати розміри всіх елементів топології фільтра які або не потребують подальшої трудомісткої оптимізації, або ж оптимізація зводиться до повторного застосування запропонованої методики із штучно зміненими вимогами до характеристики, які базуються на даних про відхилення характеристики синтезованого фільтра від вимог до неї. Розроблена методика виявилася адекватною при розробці запропонованих хвилеводно-планарних фільтрів, побудованих на відрізках антиподальної хвилеводно-щілинної лінії у позамежовому прямокутному  хвилеводі за умови значного перекриття її гребенів, при якому скорочення резонаторів відносно половини довжини хвилі досягає 80 %. Зазначена хвилеводно-планарна реалізація фільтра на позамежовому прямокутному хвилеводі дозволяє значно розширити смугу частот непропускання, збільшити внесене в ній загасання і одночасно забезпечити повторюваність характеристик фільтрів без будь-яких дій по їх настроюванню.  Ефективність запропонованого підходу до реалізації фільтра і його розрахунку продемонстрована на розробці і експериментальному дослідженні фільтра діапазону 21 ГГц, який за сукупністю параметрів (втрати порядку 1 дБ, ширина смуги загородження до четвертої гармоніки центральної частоти смуги пропускання) відповідає високим вимогам щодо електричних характеристик і технологічності. Показано, що розроблена методика синтезу подібних фільтрів залишається актуальною при синтезі фільтрів із відносною шириною смуги частот пропускання до 40 %

Online condition monitoring of MV cable feeders using Rogowski coil sensors for PD measurements

Condition monitoring is a highly effective prognostic tool for incipient insulation degradation to avoid sudden failures of electrical components and to keep the power network in operation. Improved operational performance of the sensors and effective measurement techniques could enable the development of a robust monitoring system. This paper addresses two main aspects of condition monitoring: an enhanced design of an induction sensor that has the capability of measuring partial discharge (PD) signals emerging simultaneously from medium voltage cables and transformers, and an integrated monitoring system that enables the monitoring of a wider part of the cable feeder. Having described the conventional practices along with the authors’ own experiences and research on non-intrusive solutions, this paper proposes an optimum design of a Rogowski coil that can measure the PD signals from medium voltage cables, its accessories, and the distribution transformers. The proposed PD monitoring scheme is implemented using the directional sensitivity capability of Rogowski coils and a suitable sensor installation scheme that leads to the development of an integrated monitoring model for the components of a MV cable feeder. Furthermore, the paper presents forethought regarding huge amount of PD data from various sensors using a simplified and practical approach. In the perspective of today’s changing grid, the presented idea of integrated monitoring practices provide a concept towards automated condition monitoring.fi=vertaisarvioitu|en=peerReviewed

Full Duplex CMOS Transceiver with On-Chip Self-Interference Cancelation

abstract: The demand for the higher data rate in the wireless telecommunication is increasing rapidly. Providing higher data rate in cellular telecommunication systems is limited because of the limited physical resources such as telecommunication frequency channels. Besides, interference with the other users and self-interference signal in the receiver are the other challenges in increasing the bandwidth of the wireless telecommunication system. Full duplex wireless communication transmits and receives at the same time and the same frequency which was assumed impossible in the conventional wireless communication systems. Full duplex wireless communication, compared to the conventional wireless communication, doubles the channel efficiency and bandwidth. In addition, full duplex wireless communication system simplifies the reusing of the radio resources in small cells to eliminate the backhaul problem and simplifies the management of the spectrum. Finally, the full duplex telecommunication system reduces the costs of future wireless communication systems. The main challenge in the full duplex wireless is the self-interference signal at the receiver which is very large compared to the receiver noise floor and it degrades the receiver performance significantly. In this dissertation, different techniques for the antenna interface and self-interference cancellation are proposed for the wireless full duplex transceiver. These techniques are designed and implemented on CMOS technology. The measurement results show that the full duplex wireless is possible for the short range and cellular wireless communication systems.Dissertation/ThesisDoctoral Dissertation Engineering 201

Study of mm-wave Fixed Beam and Frequency Beam-Scanning Antenna Arrays

Millimeter-wave frequencies are anticipated to be widely adapted for future wireless communication systems to resolve the demand of high data-rate and capacity issues. The millimeter-wave frequency range offers wide spectrum and a shift for most newly developing technologies as the microwave and lower frequency bands are becoming overcrowded and congested. These high frequency bands offer short wavelengths which has enabled the researchers to design and implement compact and adaptable antenna solutions. This research focuses on the implementation, transformation and modification of antenna structures used in lower frequency bands to millimeter-wave applications with high gain and multi-band and wideband performances. The first part of the thesis presents a microstrip patch array antenna with high gain in the upper 26 GHz range for 5G applications. The tolerance of the antenna, on widely used Rogers RT/duroid 5880 substrate, is observed with the edge-fed structure when curved in both concave and convex directions. In the second part of the thesis, 20 rectangular loops are arranged in a quasi-rhombic shaped planar microstrip grid array antenna configuration with dual-band millimeter-wave performance. A comparison with equal sized microstrip patch array is also presented to analyse the performance. The antenna operates in the upper 26 GHz band and has two frequency bands in close proximity. The third part of the thesis discusses the transition from wire Bruce array antenna to planar technology. Having been around for nearly a century and despite the simplicity of structure, the research community has not extended the concept of Bruce array antenna for further research. The proposed planar Bruce array antenna operates in three frequency v bands with optimization focus on 28.0 GHz band that has a directive fan-beam radiation pattern at broadside whereas the other two frequency ranges, above 30 GHz, have dual-beam radiation patterns which provide radiation diversity in narrow passages. The final part of the thesis deals with the transformation and modification of wire Bruce array antenna geometry to edge-fed printed leaky-wave antennas for millimeter-wave frequency scanning applications. In the first approach, the lengths of the unit-cell are optimised, without any additional circuitry, to enable two scanning ranges and mitigate the Open-Stopband, at broadside, for seamless scanning in the first range. A Klopfen-stein tapered divider is then deployed to make a linear array of the proposed antenna to achieve high gain. In the second approach, the horizontal and vertical lengths of the meandered unit-cell are replaced with semi-circular and novel bowtie elements, respectively, to obtain wide scanning range. The numerical results and optimizations have been performed using CST Micro-wave Studio where the effects of metallization and dielectric losses are properly consid-ered. The prototypes of the proposed antennas have been fabricated and experimentally validated

Antenna Designs Aiming at the Next Generation of Wireless Communication

Millimeter-wave (mm-wave) frequencies have drawn large attention, specically for the fifth generation (5G) of wireless communication, due to their capability to provide high data-rates. However, design and characterization of the antenna system in wireless communication will face new challenges when we move up to higher frequency bands. The small size of the components at higher frequencies will make the integration of the antennas in the system almost inevitable. Therefore, the individual characterization of the antenna can become more challenging compared to the previous generations.This emphasizes the importance of having a reliable, simple and yet meaningful Over-the-Air (OTA) characterization method for the antenna systems. To avoid the complexity of using a variety of propagation environments in the OTA performance characterization, two extreme or edge scenarios for the propagation channels are presented, i.e., the Rich Isotropic Multipath (RIMP) and Random Line-of-Sight (Random-LoS). MIMO efficiency has been defined as a Figure of Merit (FoM), based on the Cumulative Distribution Function (CDF) of the received signal, due to the statistical behavior of the signal in both RIMP and Random-LoS. Considering this approach, we have improved the design of a wideband antenna for wireless application based on MIMO efficiency as the FoM of the OTA characterization in a Random-LoS propagation environment. We have shown that the power imbalance and the polarization orthogonality plays major roles determining the 2-bitstream MIMO performance of the antenna in Random-LoS. In addition, a wideband dual-polarized linear array is designed for an OTA Random-LoS measurement set-up for automotive wireless systems. The next generation of wireless communications is extended throughout multiple narrow frequency bands, varying within 20-70 GHz. Providing an individual antenna system for each of these bands may not be feasible in terms of cost, complexity and available physical space. Therefore, Ultra-Wideband (UWB) antenna arrays, coveringmultiple mm-wave frequency bands represent a versatile candidate for these antenna systems. In addition to having wideband characteristics, these antennas should offer an easy integration capability with the active modules. We present a new design of UWB planar arrays for mm-wave applications. The novelty is to propose planar antenna layouts to provide large bandwidth at mm-wave frequencies, using simplified standard PCB manufacturing techniques. The proposed antennas are based on Tightly Coupled Dipole Arrays (TCDAs) concept with integrated feeding network

Harnessing optical micro-combs for microwave photonics

In the past decade, optical frequency combs generated by high-Q micro-resonators, or micro-combs, which feature compact device footprints, high energy efficiency, and high-repetition-rates in broad optical bandwidths, have led to a revolution in a wide range of fields including metrology, mode-locked lasers, telecommunications, RF photonics, spectroscopy, sensing, and quantum optics. Among these, an application that has attracted great interest is the use of micro-combs for RF photonics, where they offer enhanced functionalities as well as reduced size and power consumption over other approaches. This article reviews the recent advances in this emerging field. We provide an overview of the main achievements that have been obtained to date, and highlight the strong potential of micro-combs for RF photonics applications. We also discuss some of the open challenges and limitations that need to be met for practical applications.Comment: 32 Pages, 13 Figures, 172 Reference

Design and characterization of monolithic millimeter-wave active and passive components, low-noise and power amplifiers, resistive mixers, and radio front-ends

This thesis focuses on the design and characterization of monolithic active and passive components, low-noise and power amplifiers, resistive mixers, and radio front-ends for millimeter-wave applications. The thesis consists of 11 publications and an overview of the research area, which also summarizes the main results of the work. In the design of millimeter-wave active and passive components the main focus is on realized CMOS components and techniques for pushing nanoscale CMOS circuits beyond 100 GHz. Test structures for measuring and analyzing these components are shown. Topologies for a coplanar waveguide, microstrip line, and slow-wave coplanar waveguide that are suitable for implementing transmission lines in nanoscale CMOS are presented. It is demonstrated that the proposed slow-wave coplanar waveguide improves the performance of the transistor-matching networks when compared to a conventional coplanar waveguide and the floating slow-wave shield reduces losses and simplifies modeling when extended below other passives, such as DC decoupling and RF short-circuiting capacitors. Furthermore, wideband spiral transmission line baluns in CMOS at millimeter-wave frequencies are demonstrated. The design of amplifiers and a wideband resistive mixer utilizing the developed components in 65-nm CMOS are shown. A 40-GHz amplifier achieved a +6-dBm 1-dB output compression point and a saturated output power of 9.6 dBm with a miniature chip size of 0.286 mm². The measured noise figure and gain of the 60-GHz amplifier were 5.6 dB and 11.5 dB, respectively. The V-band balanced resistive mixer achieved a 13.5-dB upconversion loss and 34-dB LO-to-RF isolation with a chip area of 0.47 mm². In downconversion, the measured conversion loss and 1-dB input compression point were 12.5 dB and +5 dBm, respectively. The design and experimental results of low-noise and power amplifiers are presented. Two wideband low-noise amplifiers were implemented in a 100-nm metamorphic high electron mobility transistor (HEMT) technology. The amplifiers achieved a 22.5-dB gain and a 3.3-dB noise figure at 94 GHz and a 18-19-dB gain and a 5.5-7.0-dB noise figure from 130 to 154 GHz. A 60-GHz power amplifier implemented in a 150-nm pseudomorphic HEMT technology exhibited a +17-dBm 1-dB output compression point with a 13.4-dB linear gain. In this thesis, the main system-level aspects of millimeter-wave transmitters and receivers are discussed and the experimental circuits of a 60-GHz transmitter front-end and a 60-GHz receiver with an on-chip analog-to-digital converter implemented in 65-nm CMOS are shown. The receiver exhibited a 7-dB noise figure, while the saturated output power of the transmitter front-end was +2 dBm. Furthermore, a wideband W-band transmitter front-end with an output power of +6.6 dBm suitable for both image-rejecting superheterodyne and direct-conversion transmission is demonstrated in 65-nm CMOS