Perspectives pour le laboratoire d'électronique et de traitement du signa
Piece d'horlogerie comprenant un mouvement horloger (2) pourvu d'un affichage analogique (14). La roue (4) comprend un plateau (8) avec une denture (6) definie par son bord externe et un arbre (10). Un dispositif de detection de... more
Piece d'horlogerie comprenant un mouvement horloger (2) pourvu d'un affichage analogique (14). La roue (4) comprend un plateau (8) avec une denture (6) definie par son bord externe et un arbre (10). Un dispositif de detection de la position angulaire de la roue (4) comprend un capteur magnetique ou capacitif (20) dont l'organe de detection, notamment une bobine plane en spirale (24) sert a la detection d'une variation de presence de la matiere, notamment d'un metal conducteur non magnetique constituant le plateau (8). Ce plateau presente au moins une ouverture (16) situee dans sa region intermediaire entre un trou central (18) et la denture (6). L'ouverture (16) definit un demi-axe de reference de la roue (4) dont la position angulaire est determinee par le dispositif de detection prevu.
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Since the sixties, movies such as “2001: A Space Odyssey” have familiarized us with the idea of com-puters that can speak and hear just as a human being does. Automatic speech recogni-tion (ASR) is the technol-ogy that allows machines to... more
Since the sixties, movies such as “2001: A Space Odyssey” have familiarized us with the idea of com-puters that can speak and hear just as a human being does. Automatic speech recogni-tion (ASR) is the technol-ogy that allows machines to interpret human speech (i.e. to answer the ques-tion: What is being said?). The machine ”speaks back“, either by playing pre-recorded messages or by using text-to-speech (TTS) technology.
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In this paper, a model is proposed to analyze the influence of timing imperfections on ultra-wide bandwith (UWB) time-hopping spread-spectrum (TH-SS) signaling schemes, where N pulses are coherently added to increase the received... more
In this paper, a model is proposed to analyze the influence of timing imperfections on ultra-wide bandwith (UWB) time-hopping spread-spectrum (TH-SS) signaling schemes, where N pulses are coherently added to increase the received signal-to-noise ratio (SNR). Based on this model, we derive asymptotical (valid for large N) expressions for the received signal after pulse summation and matched filtering. As an application example, we study the influence of timing jitter and frequency offsets on the maximum SNR, assuming a 2nd derivative Gaussian pulse shape. The analytical results we obtain are verified with numerical simulations.
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The Quantime project aims at developing a miniature atomic clock suited for the telecom market, requiring a wide operating temperature range (from -40 to +85°C), and a low production cost. The CPT (Coherent Population Trapping) technique... more
The Quantime project aims at developing a miniature atomic clock suited for the telecom market, requiring a wide operating temperature range (from -40 to +85°C), and a low production cost. The CPT (Coherent Population Trapping) technique for atomic interrogation is used for miniaturization and low power consumption. In the first phase of the project, the clock architecture was chosen, and the main sub-systems were developed. A clock breadboarding demonstrator was assembled and the measured Allan deviation of 1E-11 at 400 s confirms the operation of all the sub-systems.
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The world of global navigation satellite systems has been enhanced with several new or improved signals in space aiming to optimize accuracy, reliability, navigation solution, and interoperability between different constellations.... more
The world of global navigation satellite systems has been enhanced with several new or improved signals in space aiming to optimize accuracy, reliability, navigation solution, and interoperability between different constellations. However, such developments bring various challenges to the receivers ’ designers. For example, acquisition and tracking stages turn into more complex processes while handling the increasing bandwidth requires additional processing power. In this context, we study the code tracking of Galileo E5ab in a full band or of only one of its components, i.e., either E5a or E5b. More specifically, an architecture for tracking the E5 pilot channel as an AltBOC(15,10) or BPSK(10) modulation is introduced, and the performance of well-known discriminator types is analyzed using analytical derivations and simulations of linearity and stability regions, thermal noise tracking errors, multipath error envelopes and tracking thresholds. Different parameters, such as the fron...
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The paper presents an analog, current-mode circuit that cal- culates a distance between the neuron weights vectors W and the input learning patterns X. The circuit can be used as a component of dierent self-organizing neural networks (NN)... more
The paper presents an analog, current-mode circuit that cal- culates a distance between the neuron weights vectors W and the input learning patterns X. The circuit can be used as a component of dierent self-organizing neural networks (NN) implemented in the CMOS technol- ogy. In Self-Organizing Maps (SOM) as well as in NNs using the Neural Gas or the Winner Takes All (WTA) learning algorithms, to calculate the distance between X and W , the same circuit can be used that makes it a universal structure. Detailed system level simulations of the WTA NN and the Kohonen SOM showed that using both the Euclidean (L2) and the Manhattan (L1) distance measures leads to similar learning results. For this reason, the L1 measure has been implemented, as in this case the circuit is much simpler than the one using the L2 distance, resulting in very low chip area and low power dissipation. This enables including even large NNs in miniaturized portable devices, such as sensors in Wireless Sensor Netw...
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PROBLEM TO BE SOLVED: To provide a frequency generation device which can be used for a part of a digital system used in a radio communication call system such as a clock for a call device, which can stand a long use with less influence by... more
PROBLEM TO BE SOLVED: To provide a frequency generation device which can be used for a part of a digital system used in a radio communication call system such as a clock for a call device, which can stand a long use with less influence by the temperature. SOLUTION: The frequency generation device G is provided with an oscillator 10 for first frequency F1 generation, a reference frequency generation device BT, a feedback means supplying the first number nT of a pulse from the oscillator 10 to a comparison means 13, a means supplying the reference number NT of the pulse to the comparison means 13, means 13, 15 and 16 supplying a correction signal SC as the function of difference Δ between the first number nT and the reference number NT and a means which is the correction circuit 17 of the oscillation frequency F1 of the first oscillator 10 and which is controlled by the signal SC.
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A self-winding movement has been developed with the accuracy of an electronic quartz movement [1]. This is achieved by replacing the escapement mechanism and the balance wheel/hairspring resonator by an electromechanical escapement and a... more
A self-winding movement has been developed with the accuracy of an electronic quartz movement [1]. This is achieved by replacing the escapement mechanism and the balance wheel/hairspring resonator by an electromechanical escapement and a quartz tuning fork resonator. At the end of the gear train is a miniature generator turning constantly at a speed of about 7 revolutions per second. This micro generator supplies the energy to operate an integrated circuit containing a quartz oscillator. The frequency of the AC generator signal is compared to the frequency of the quartz resonator and the generator is electrically synchronised to maintain its speed according to the quartz resonator's signal. The generator being driven by the main spring through the gear train coupled to the hands, this principle leads to a perfectly constant speed of the hands and a totally quiet movement. The energy for the movement being stored in the main spring, the timepiece has no primary or rechargeable ba...
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ABSTRACT This paper describes a system to drive piezoelectric actuators over more than one decade of voltages and one octave of frequencies, in order to perform high-speed complex impedance characterization at a user chosen voltage... more
ABSTRACT This paper describes a system to drive piezoelectric actuators over more than one decade of voltages and one octave of frequencies, in order to perform high-speed complex impedance characterization at a user chosen voltage excitation level. This characterization provides information about electrical and mechanical characteristics of the device under tests. An electronic board was developed and components were chosen in order to provide high voltages. Optimized algorithms were implemented into a DSP to insure high accuracy measurements of impedance and phase of the load and to minimize process time.
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In this paper, the design of a low-noise amplifier (LNA) for a 32x32 pixel microelectrode array (MEA) is presented. Its gain and noise amount to 50 dB and 10 μVrms, respectively, at a bandwidth of 66 kHz. The LNA consumes less than 85 μW.... more
In this paper, the design of a low-noise amplifier (LNA) for a 32x32 pixel microelectrode array (MEA) is presented. Its gain and noise amount to 50 dB and 10 μVrms, respectively, at a bandwidth of 66 kHz. The LNA consumes less than 85 μW. The integrated offset compensation circuit makes the system less sen- sitive to mismatch and variations in the culture medium biasing voltage. A sample & hold (S&H) buffer stores the amplified input signals locally, thereby realising an electronic shutter function. This allows for simultaneous acquisition of all pixels. The on-chip logic permits individual selection of every single pixel at any time. As a result, regions of interest (ROIs) of any size can be defined. Accordingly, the entire cell culture or subregions can be observed at a high sampling rate. Moreover, each pixel is equipped with a stimulation circuitry. Centered around a programmable SRAM cell, it offers the creation of complex stimulation patterns on the MEA. The entire circuit has been layouted in 180 nm, 3.3 V CMOS technology and covers an area of 60x60 μm 2 .
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ABSTRACT In this paper, we present the characterization results of an optimized 4.6 GHz frequency synthesizer ASIC targeted for miniature atomic clock applications. Fabricated into a 130 nm RF CMOS process, the circuit occupies an active... more
ABSTRACT In this paper, we present the characterization results of an optimized 4.6 GHz frequency synthesizer ASIC targeted for miniature atomic clock applications. Fabricated into a 130 nm RF CMOS process, the circuit occupies an active area of 2 mm2 and consumes 15 mW of power. The measured phase noise is about −85 dBc/Hz in the range of 2 kHz to 100 kHz frequency offset from the carrier. The circuit was used as RF synthesizer in an experimental cesium atomic clock setup. The obtained clock stability of 5×10−11 at τ = 1 second corresponds to the stability obtained with a laboratory synthesizer on the same setup, and is limited by the signal-to-noise ratio of the detected CPT signal. The theoretical stability limit due to the ASIC phase noise is 2×10−11 τ −1/2, which is not limiting the measured clock stability.
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The world of global navigation satellite systems has been enhanced with several new or improved signals in space aiming to optimize accuracy, reliability, navigation solution, and interoperability between different constellations.... more
The world of global navigation satellite systems has been enhanced with several new or improved signals in space aiming to optimize accuracy, reliability, navigation solution, and interoperability between different constellations. However, such developments bring various challenges to the receivers ’ designers. For example, acquisition and tracking stages turn into more complex processes while handling the increasing bandwidth requires additional processing power. In this context, we study the code tracking of Galileo E5ab in a full band or of only one of its components, i.e., either E5a or E5b. More specifically, an architecture for tracking the E5 pilot channel as an AltBOC(15,10) or BPSK(10) modulation is introduced, and the performance of well-known discriminator types is analyzed using analytical derivations and simulations of linearity and stability regions, thermal noise tracking errors, multipath error envelopes and tracking thresholds. Different parameters, such as the fron...
Research Interests:
The paper presents an analog, current-mode circuit that cal- culates a distance between the neuron weights vectors W and the input learning patterns X. The circuit can be used as a component of dierent self-organizing neural networks (NN)... more
The paper presents an analog, current-mode circuit that cal- culates a distance between the neuron weights vectors W and the input learning patterns X. The circuit can be used as a component of dierent self-organizing neural networks (NN) implemented in the CMOS technol- ogy. In Self-Organizing Maps (SOM) as well as in NNs using the Neural Gas or the Winner Takes All (WTA) learning algorithms, to calculate the distance between X and W , the same circuit can be used that makes it a universal structure. Detailed system level simulations of the WTA NN and the Kohonen SOM showed that using both the Euclidean (L2) and the Manhattan (L1) distance measures leads to similar learning results. For this reason, the L1 measure has been implemented, as in this case the circuit is much simpler than the one using the L2 distance, resulting in very low chip area and low power dissipation. This enables including even large NNs in miniaturized portable devices, such as sensors in Wireless Sensor Netw...
Research Interests:
Research Interests:
PROBLEM TO BE SOLVED: To provide a frequency generation device which can be used for a part of a digital system used in a radio communication call system such as a clock for a call device, which can stand a long use with less influence by... more
PROBLEM TO BE SOLVED: To provide a frequency generation device which can be used for a part of a digital system used in a radio communication call system such as a clock for a call device, which can stand a long use with less influence by the temperature. SOLUTION: The frequency generation device G is provided with an oscillator 10 for first frequency F1 generation, a reference frequency generation device BT, a feedback means supplying the first number nT of a pulse from the oscillator 10 to a comparison means 13, a means supplying the reference number NT of the pulse to the comparison means 13, means 13, 15 and 16 supplying a correction signal SC as the function of difference Δ between the first number nT and the reference number NT and a means which is the correction circuit 17 of the oscillation frequency F1 of the first oscillator 10 and which is controlled by the signal SC.
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A self-winding movement has been developed with the accuracy of an electronic quartz movement [1]. This is achieved by replacing the escapement mechanism and the balance wheel/hairspring resonator by an electromechanical escapement and a... more
A self-winding movement has been developed with the accuracy of an electronic quartz movement [1]. This is achieved by replacing the escapement mechanism and the balance wheel/hairspring resonator by an electromechanical escapement and a quartz tuning fork resonator. At the end of the gear train is a miniature generator turning constantly at a speed of about 7 revolutions per second. This micro generator supplies the energy to operate an integrated circuit containing a quartz oscillator. The frequency of the AC generator signal is compared to the frequency of the quartz resonator and the generator is electrically synchronised to maintain its speed according to the quartz resonator's signal. The generator being driven by the main spring through the gear train coupled to the hands, this principle leads to a perfectly constant speed of the hands and a totally quiet movement. The energy for the movement being stored in the main spring, the timepiece has no primary or rechargeable ba...
Research Interests:
Research Interests:
Research Interests:
ABSTRACT This paper describes a system to drive piezoelectric actuators over more than one decade of voltages and one octave of frequencies, in order to perform high-speed complex impedance characterization at a user chosen voltage... more
ABSTRACT This paper describes a system to drive piezoelectric actuators over more than one decade of voltages and one octave of frequencies, in order to perform high-speed complex impedance characterization at a user chosen voltage excitation level. This characterization provides information about electrical and mechanical characteristics of the device under tests. An electronic board was developed and components were chosen in order to provide high voltages. Optimized algorithms were implemented into a DSP to insure high accuracy measurements of impedance and phase of the load and to minimize process time.
Research Interests:
Research Interests:
In this paper, the design of a low-noise amplifier (LNA) for a 32x32 pixel microelectrode array (MEA) is presented. Its gain and noise amount to 50 dB and 10 μVrms, respectively, at a bandwidth of 66 kHz. The LNA consumes less than 85 μW.... more
In this paper, the design of a low-noise amplifier (LNA) for a 32x32 pixel microelectrode array (MEA) is presented. Its gain and noise amount to 50 dB and 10 μVrms, respectively, at a bandwidth of 66 kHz. The LNA consumes less than 85 μW. The integrated offset compensation circuit makes the system less sen- sitive to mismatch and variations in the culture medium biasing voltage. A sample & hold (S&H) buffer stores the amplified input signals locally, thereby realising an electronic shutter function. This allows for simultaneous acquisition of all pixels. The on-chip logic permits individual selection of every single pixel at any time. As a result, regions of interest (ROIs) of any size can be defined. Accordingly, the entire cell culture or subregions can be observed at a high sampling rate. Moreover, each pixel is equipped with a stimulation circuitry. Centered around a programmable SRAM cell, it offers the creation of complex stimulation patterns on the MEA. The entire circuit has been layouted in 180 nm, 3.3 V CMOS technology and covers an area of 60x60 μm 2 .
Research Interests:
Research Interests:
ABSTRACT In this paper, we present the characterization results of an optimized 4.6 GHz frequency synthesizer ASIC targeted for miniature atomic clock applications. Fabricated into a 130 nm RF CMOS process, the circuit occupies an active... more
ABSTRACT In this paper, we present the characterization results of an optimized 4.6 GHz frequency synthesizer ASIC targeted for miniature atomic clock applications. Fabricated into a 130 nm RF CMOS process, the circuit occupies an active area of 2 mm2 and consumes 15 mW of power. The measured phase noise is about −85 dBc/Hz in the range of 2 kHz to 100 kHz frequency offset from the carrier. The circuit was used as RF synthesizer in an experimental cesium atomic clock setup. The obtained clock stability of 5×10−11 at τ = 1 second corresponds to the stability obtained with a laboratory synthesizer on the same setup, and is limited by the signal-to-noise ratio of the detected CPT signal. The theoretical stability limit due to the ASIC phase noise is 2×10−11 τ −1/2, which is not limiting the measured clock stability.
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We are developing an Alternative and Augmentative Communication (AAC) portable device called PictoBar which is used in speech rehabilitation therapy. PictoBar recognizes barcodes and images, such as pictograms and pictures. Then it plays... more
We are developing an Alternative and Augmentative Communication (AAC) portable device called PictoBar which is used in speech rehabilitation therapy. PictoBar recognizes barcodes and images, such as pictograms and pictures. Then it plays a sound message associated with the recognized barcode or image. This paper describes the development of the image recognition algorithm and its implementation using Codec Engine framework
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We are developing an Alternative and Augmentative Communication (AAC) portable device called PictoBar which is used in speech rehabilitation therapy. PictoBar recognizes barcodes and images, such as pictograms and pictures. Then it plays... more
We are developing an Alternative and Augmentative Communication (AAC) portable device called PictoBar which is used in speech rehabilitation therapy. PictoBar recognizes barcodes and images, such as pictograms and pictures. Then it plays a sound message associated with the recognized barcode or image. This paper describes the development of the image recognition algorithm and its implementation using Codec Engine framework