920 research outputs found

    Bi-layer Kinetic Inductance Detectors for space observations between 80-120 GHz

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    We have developed Lumped Element Kinetic Inductance Detectors (LEKID) sensitive in the frequency band from 80 to 120~GHz. In this work, we take advantage of the so-called proximity effect to reduce the superconducting gap of Aluminium, otherwise strongly suppressing the LEKID response for frequencies smaller than 100~GHz. We have designed, produced and optically tested various fully multiplexed arrays based on multi-layers combinations of Aluminium (Al) and Titanium (Ti). Their sensitivities have been measured using a dedicated closed-circle 100 mK dilution cryostat and a sky simulator allowing to reproduce realistic observation conditions. The spectral response has been characterised with a Martin-Puplett interferometer up to THz frequencies, and with a resolution of 3~GHz. We demonstrate that Ti-Al LEKID can reach an optical sensitivity of about 1.41.4 10−1710^{-17}~W/Hz0.5W/Hz^{0.5} (best pixel), or 2.22.2 10−1710^{-17}~W/Hz0.5W/Hz^{0.5} when averaged over the whole array. The optical background was set to roughly 0.4~pW per pixel, typical for future space observatories in this particular band. The performance is close to a sensitivity of twice the CMB photon noise limit at 100~GHz which drove the design of the Planck HFI instrument. This figure remains the baseline for the next generation of millimetre-wave space satellites.Comment: 7 pages, 9 figures, submitted to A&

    Physics and Applications of Laser Diode Chaos

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    An overview of chaos in laser diodes is provided which surveys experimental achievements in the area and explains the theory behind the phenomenon. The fundamental physics underpinning this behaviour and also the opportunities for harnessing laser diode chaos for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient test-bed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.Comment: Published in Nature Photonic

    Development of a Point Pyroshock Source Simulator

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    Optical Arbitrary Waveform Measurement (OAWM) on the Silicon Photonic Platform

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    We demonstrate optical arbitrary waveform measurement (OAWM) using a silicon pho-tonic spectral slicer. Exploiting maximal-ratio combining (MRC), we demonstrate the viability of the scheme by reconstructing 100-GBd 64QAM signals with high quality

    Enhanced PON Infrastructure Enabled by Silicon Photonics

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    Les systĂšmes de courte portĂ©e et de dĂ©tection directe sont le dernier/premier kilomĂštre de la fourniture des services Internet d'aujourd'hui. Deux cas d'application sont abordĂ©s dans cette thĂšse, l'un concerne l'amĂ©lioration des performances des services Internet par la Fibre-To-TheHome ou les rĂ©seaux optiques passifs (PONs). L'autre est le radio access network (RAN) pour le fronthaul. Notre objectif pour RAN est de superposer les signaux 5G sur une infrastructure PON. Nous dĂ©montrons expĂ©rimentalement la gĂ©nĂ©ration d'un signal de rĂ©partition multiplexĂ©e de frĂ©quences orthogonales (OFDM) Ă  bande latĂ©rale unique en utilisant un modulateur IQ sur puce basĂ© sur les photoniques au silicium Ă  micro-anneau. Il s'agit d'une solution Ă  coĂ»t bas permettant aux PONs d'augmenter les dĂ©bits de donnĂ©es grĂące Ă  l'utilisation d'OFDM. Nous avons gĂ©nĂ©rĂ© un signal OFDM Ă  large bande avec un ratio de suppression de bande latĂ©rale de plus de 18 dB. Afin de confirmer la robustesse de la dispersion chromatique (CD), nous transmettons le signal gĂ©nĂ©rĂ© OFDM SSB dans plus de 20 km de fibre de monomode standard. Aucun fading induit par la CD n'a Ă©tĂ© observĂ© et le taux d'erreur sur les bits Ă©tait bon. Nous proposons une solution de photoniques au silicium pour un rĂ©seau optique passif afin de mitiger l'interfĂ©rence de battement signal-signal (SSBI) dans la transmission OFDM, et de rĂ©cupĂ©rer une partie des porteuses de la liaison descendante pour une utilisation dans la liaison montante. Le sous-systĂšme recrĂ©e les interfĂ©rences Ă  une entrĂ©e du dĂ©tecteur Ă©quilibrĂ© ; le signal de donnĂ©es corrompu par SSBI est Ă  la deuxiĂšme entrĂ©e. L'annulation se produit via la soustraction dans la dĂ©tection Ă©quilibrĂ©e. Comme notre solution de photoniques au silicium (SiP) ne peut pas filtrer les signaux idĂ©alement, nous examinons un facteur d'Ă©chelle introduit dans la dĂ©tection Ă©quilibrĂ©e qui peut balancer les effets de filtrage non idĂ©aux. Nous montrons expĂ©rimentalement l'annulation de l'interfĂ©rence donne de bonnes performances mĂȘme avec une porteuse faible, soit pour un ratio porteuse/signal ultra bas de 0 dB. Bien que notre solution soit sensible aux effets de la tempĂ©rature, notre dĂ©monstration expĂ©rimentale montre que le rĂ©glage de la frĂ©quence rĂ©sonante peut dĂ©river jusqu'Ă  12 GHz de la valeur ciblĂ©e et prĂ©senter toujours de bonnes performances. Nous effectuons des simulations extensives du schĂ©ma d'annulation SSBI proposĂ©, et suggĂ©rons une diverse conception polarisĂ©e pour le sous-systĂšme SiP. Nous examinons via la simulation la vulnĂ©rabilitĂ© Ă  la variation de tempĂ©rature et introduisons une nouvelle mĂ©trique de performance : Q-facteur minimum garanti. Nous nous servons de cette mĂ©trique pour Ă©valuer la robustesse d'annulation SSBI contre la dĂ©rive de frĂ©quence induite par les changements de tempĂ©rature. Nous maximisons l'efficacitĂ© spectrale sous diffĂ©rentes conditions du systĂšme en balayant les paramĂštres de conception contrĂŽlables. Finalement, les rĂ©sultats de la simulation du systĂšme fournissent des indications sur la conception du rĂ©sonateur micro-anneau, ainsi que sur le choix de la bande de garde et du format de modulation pour obtenir la plus grande efficacitĂ© spectrale. Finalement, nous nous concentrons sur la superposition des signaux 5G sur une infrastructure PON pour RAN. Nous expĂ©rimentalement validons un sous-systĂšme photonique au silicium conçu pour les rĂ©seaux optiques passifs avec rĂ©utilisation de porteuses et compatibilitĂ© radiosur-fibre (RoF) analogique 5G. Le sous-systĂšme permet la dĂ©tection simultanĂ©e des signaux RoF et du signal PON transmis dans une seule tranche assignĂ©e de longueur d'onde. Tout en maintenant une qualitĂ© suffisante de dĂ©tection des signaux RoF et PON, il n'y a que la puissance minimale de la porteuse qui est extraite pour chaque dĂ©tection, ce qui conserve ainsi la puissance de la porteuse pour la modulation de liaison montante. Nous rĂ©alisons une suppression efficace du signal de liaison descendante en laissant une porteuse propre et forte pour la remodulation. Nous dĂ©montrons expĂ©rimentalement le signal RoF de liaison montante via un modulateur Ă  micro-anneau. Nous avons dĂ©tectĂ© avec succĂšs un signal Ă  large bande de 8 GHz et cinq signaux RoF de 125 MHz simultanĂ©ment. Et deux signaux RoF de 125 MHz sont remodulĂ©s sur la mĂȘme porteuse. Le signal RoF de liaison montante gĂ©nĂ©rĂ© est de 13 dB de plus que les signaux de liaison descendante, ce qui indique leur robustesse contre la diaphonie des signaux rĂ©siduels de la liaison descendante.Short reach, direct detection systems are the last/first mile of today's internet service provision. Two use cases are addressed in this thesis, one is for enhancing performance of Internet services on fiber-to-the-home or passive optical networks (PON). The other is radio access networks (RAN) for fronthaul. Our focus for RAN is to overlay 5G signals on a PON infrastructure. We experimentally demonstrate the generation of a single-sideband orthogonal frequency division multiplexed (OFDM) signal using an on-chip silicon photonics microring-based IQ modulator. This is a low cost solution enabling PONs to increase data rates through the use of OFDM. We generated a wideband OFDM signal with over 18 dB sideband suppression ratio. To confirm chromatic dispersion (CD) robustness, we transmit the generated SSB OFDM signal over 20 km of standard single mode fiber. No CD-induced fading was observed and bit error rate was good. We propose a silicon photonics solution for a passive optical network to mitigate signal-signal beat interference (SSBI) in OFDM transmission, and to recuperate a part of the downlink carrier for use in the uplink. The subsystem recreates the interference at one balanced detector input; the data signal corrupted with SSBI is at the second input. Cancellation occurs via subtraction in the balanced detection. As our silicon photonics (SiP) solution cannot filter the signals ideally, we examine a scaling factor to be introduced to the balanced detection that can trade-off the non-ideal filtering effects. We show experimentally that the interference is cancelled, allowing good performance even with a weak carrier, that is, for ultra low carrier to signal ratio of 0 dB. Although our solution is sensitive to temperature effects, our experimental demonstration shows the tuning of the resonant frequency can drift by as much as 12 GHz from the targeted value and still provide good performance. We perform extensive simulations of the proposed SSBI cancellation scheme, and suggest a polarization diverse design for the SiP subsystem. We examine via simulation the vulnerability to temperature variation and introduce a new performance metric: minimum guaranteed Qfactor. We use this metric to evaluate the SSBI cancellation robustness against the frequency drift induced by temperature changes. We maximize the spectral efficiency under different system conditions by sweeping the controllable design parameters. Finally the system simulation results provide guidance on the microring resonator design, as well as choice of guard band and modulation format to achieve the highest spectral efficiency. Finally, we turn to focus on overlay 5G signals on a PON infrastructure for RAN. We experimentally validate a silicon photonic subsystem designed for passive optical networks with carrier reuse and 5G analog radio-over-fiber (RoF) compatibility. The subsystem enables the simultaneous detection of RoF signals and a PON signal transmitted in a single assigned wavelength slot. While maintaining sufficient quality of RoF and PON signal detection, only the minimum carrier power is leached off for each detection, thus conserving carrier power for uplink modulation. We realize effective downlink signal suppression to leave a clean and strong carrier for remodulation. We demonstrate experimentally the RoF uplink signal via a micro ring modulator. We successfully detected an 8 GHz broadband signal and five 125 MHz RoF signals simultaneously. And two 125 MHz radio over fiber signals are remodulated onto the same carrier. The generated uplink RoF signal is 13 dB over the downlink signals, indicating their robustness against the crosstalk from residual downlink signals

    Optical based noninvasive glucose monitoring sensor prototype

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    Diabetes mellitus claims millions of lives every year. It affects the body in various ways by leading to many serious illnesses and premature mortality. Heart and kidney diseases, which are caused by diabetes, are increasing at an alarming rate. In this paper, we report a study of a noninvasive measurement technique to determine the glucose levels in the human body. Current existing methods to quantify the glucose level in the blood are predominantly invasive that involve taking the blood samples using finger pricking. In this paper, we report a spectroscopy-based noninvasive glucose monitoring system to measure glucose concentration. Near-infrared transmission spectroscopy is used and in vitro experiments are conducted, as well as in vivo. Our experimental study confirms a correlation between the sensor output voltage and glucose concentration levels. We report a low-cost prototype of spectroscopy-based noninvasive glucose monitoring system that demonstrates promising results in vitro and establishes a relationship between the optical signals and the changing levels of blood–glucose concentration

    Advanced CMOS Integrated Circuit Design and Application

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    The recent development of various application systems and platforms, such as 5G, B5G, 6G, and IoT, is based on the advancement of CMOS integrated circuit (IC) technology that enables them to implement high-performance chipsets. In addition to development in the traditional fields of analog and digital integrated circuits, the development of CMOS IC design and application in high-power and high-frequency operations, which was previously thought to be possible only with compound semiconductor technology, is a core technology that drives rapid industrial development. This book aims to highlight advances in all aspects of CMOS integrated circuit design and applications without discriminating between different operating frequencies, output powers, and the analog/digital domains. Specific topics in the book include: Next-generation CMOS circuit design and application; CMOS RF/microwave/millimeter-wave/terahertz-wave integrated circuits and systems; CMOS integrated circuits specially used for wireless or wired systems and applications such as converters, sensors, interfaces, frequency synthesizers/generators/rectifiers, and so on; Algorithm and signal-processing methods to improve the performance of CMOS circuits and systems

    CMOS ASIC Design of Multi-frequency Multi-constellation GNSS Front-ends

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    With the emergence of the new global navigation satellite systems (GNSSs) such as Galileo, COMPASS and GLONASS, the US Global Positioning System (GPS) has new competitors. This multiplicity of constellations will offer new services and a much better satellite coverage. Public regulated service (PRS) is one of these new services that Galileo, the first global positioning service under civilian control, will offers. The PRS is a proprietary encrypted navigation designed to be more reliable and robust against jamming and provides premium quality in terms of position and timing and continuity of service, but it requires the use of FEs with extended capabilities. The project that this thesis starts from, aims to develop a dual frequency (E1 and E6) PRS receiver with a focus on a solution for professional applications that combines affordability and robustness. To limit the production cost, the choice of a monolithic design in a multi-purpose 0.18 ”m complementary metal-oxide-semiconductor (CMOS) technology have been selected, and to reduce the susceptibility to interference, the targeted receiver is composed of two independent FEs. The first ASIC described here is such FEs bundle. Each FE is composed of a radio frequency (RF) chain that includes a low-noise amplifier (LNA), a quadrature mixer, a frequency synthesizer (FS), two intermediate frequency (IF) filters, two variable-gain amplifiers (VGAs) and two 6-bit flash analog-to-digital converters (ADCs). Each have an IF bandwidth of 50 MHz to accommodate the wide-band PRS signals. The FE achieves a 30 dB of dynamic gain control at each channel. The complete receivers occupies a die area of 11.5 mm2 while consuming 115 mW from a supply of a 1.8 V. The second ASIC that targets civilian applications, is a reconfigurable single-channel FE that permits to exploit the interoperability among GNSSs. The FE can operate in two modes: a ¿narrow-band mode¿, dedicated to Beidou-B1 with an IF bandwidth of 8 MHz, and a ¿wide-band mode¿ with an IF bandwidth of 23 MHz, which can accommodate simultaneous reception of Beidou-B1/GPS-L1/Galileo-E1. These two modes consumes respectively 22.85 mA and 28.45 mA from a 1.8 V supply. Developed with the best linearity in mind, the FE shows very good linearity with an input-referred 1 dB compression point (IP1dB) of better than -27.6 dBm. The FE gain is stepwise flexible from 39 dB and to a maximum of 58 dB. The complete FE occupies a die area of only 2.6 mm2 in a 0.18 ”m CMOS. To also accommodate the wide-band PRS signals in the IF section of the FE, a highly selective wide-tuning-range 4th-order Gm-C elliptic low-pass filter is used. It features an innovative continuous tuning circuit that adjusts the bias current of the Gm cell¿s input stage to control the cutoff frequency. With this circuit, the power consumption is proportional to the cutoff frequency thus the power efficiency is achieved while keeping the linearity near constant. Thanks to a Gm switching technique, which permit to keep the signal path switchless, the filter shows an extended tuning of the cutoff frequency that covers continuously a range from 7.4 MHz to 27.4 MHz. Moreover the abrupt roll-off of up to 66 dB/octave, can mitigate out-of-band interference. The filter consumes 2.1 mA and 7.5 mA at its lowest and highest cutoff frequencies respectively, and its active area occupies, 0.23 mm2. It achieves a high input-referred third-order intercept point (IIP3) of up to -1.3 dBVRMS

    Improving the mechanistic study of neuromuscular diseases through the development of a fully wireless and implantable recording device

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    Neuromuscular diseases manifest by a handful of known phenotypes affecting the peripheral nerves, skeletal muscle fibers, and neuromuscular junction. Common signs of these diseases include demyelination, myasthenia, atrophy, and aberrant muscle activity—all of which may be tracked over time using one or more electrophysiological markers. Mice, which are the predominant mammalian model for most human diseases, have been used to study congenital neuromuscular diseases for decades. However, our understanding of the mechanisms underlying these pathologies is still incomplete. This is in part due to the lack of instrumentation available to easily collect longitudinal, in vivo electrophysiological activity from mice. There remains a need for a fully wireless, batteryless, and implantable recording system that can be adapted for a variety of electrophysiological measurements and also enable long-term, continuous data collection in very small animals. To meet this need a miniature, chronically implantable device has been developed that is capable of wirelessly coupling energy from electromagnetic fields while implanted within a body. This device can both record and trigger bioelectric events and may be chronically implanted in rodents as small as mice. This grants investigators the ability to continuously observe electrophysiological changes corresponding to disease progression in a single, freely behaving, untethered animal. The fully wireless closed-loop system is an adaptable solution for a range of long-term mechanistic and diagnostic studies in rodent disease models. Its high level of functionality, adjustable parameters, accessible building blocks, reprogrammable firmware, and modular electrode interface offer flexibility that is distinctive among fully implantable recording or stimulating devices. The key significance of this work is that it has generated novel instrumentation in the form of a fully implantable bioelectric recording device having a much higher level of functionality than any other fully wireless system available for mouse work. This has incidentally led to contributions in the areas of wireless power transfer and neural interfaces for upper-limb prosthesis control. Herein the solution space for wireless power transfer is examined including a close inspection of far-field power transfer to implanted bioelectric sensors. Methods of design and characterization for the iterative development of the device are detailed. Furthermore, its performance and utility in remote bioelectric sensing applications is demonstrated with humans, rats, healthy mice, and mouse models for degenerative neuromuscular and motoneuron diseases
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