Abstract: A method for measuring, using a radar or sonar, the velocity with respect to the ground of a carrier moving parallel to the ground, includes the following steps: a) orienting the line of sight of the radar or sonar toward the ground; b) emitting a plurality of radar or sonar signals (P1-PN) that are directed toward the ground, and acquiring respective echo signals (E1-EN); c) processing the acquired echo signals so as to obtain, for one or more echo delay values, a corresponding Doppler spectrum; d) for the or at least one the echo delay value, determining a high cut-off frequency of the corresponding Doppler spectrum; and e) computing the velocity of the carrier with respect to the ground on the basis of the one or more high cut-off frequencies. A system allowing such a method to be implemented.

Abstract: The present invention relates to a method of compressed sensing of a spectrally-sparse signal within a given spectral band, the received signal being mixed (820) over a sensing frame with a pulse train scrolling with a repetition frequency linearly modulated over time within this frame. The result of mixing is filtered (830) by means of a low-pass filtering and sampled (840) at a non-uniform rate equal to the repetition frequency, to result in complex samples representative of the received signal. The spectrum of the received signal can be estimated by weighting by means of the complex samples the spectral values of a pulse into a plurality of frequency equidistributed in the band, and by summing up these weighted values for each of these frequencies. An estimate of the received signal is thereby deduced by inverse Fourier transform. The spectral band can be scanned based on the spectrum thus estimated.

Abstract: Radar measuring device including: a first generator of a first periodic radar signal whose frequency varies linearly, over at least one portion Tramp of a period Tin, in a frequency band B; a transmit antenna coupled to an output of the first generator and configured to transmit the first radar signal; a second generator of a second periodic radar signal whose frequency varies linearly, over said portion Tramp of the period Tin, in the frequency band B, which is generated with the same start-up phase as the first radar signal and having, relative to the first radar signal, a configurable delay ?mix; a receive antenna configured to receive at least one echo of the first radar signal; a mixer comprising a first input coupled to the receive antenna and a second input coupled to an output of the second generator.

Abstract: A radar measuring device including at least: a circuit for generating a radar signal RFIN(t); an emitting antenna; an injection-locked oscillator; a first power divider comprising an input coupled to an output of the circuit for generating the radar signal RFIN(t), a first output coupled to the emitting antenna, and a second output to an input of the injection-locked oscillator which is configured to be locked over a portion of an effective band B of the radar signal RFIN(t); a receiving antenna intended to receive a reflected radar signal RFIN_REFL(t); a mixer comprising a first input coupled to the receiving antenna, a second input coupled to an output of the injection-locked oscillator, and an output coupled to an input to a signal processing circuit.

Abstract: A generator of a frequency modulated radar signal, comprising: a generator of a periodic signal frequency modulated over a part Tramp of a period T, corresponding to a square signal of which the frequency varies linearly in a first frequency band Bin of central frequency fin; an oscillator generating a sinusoidal signal of frequency fc>fin and comprised in a second frequency band Bamp>Bin and corresponding to the linear variation of the frequency of the radar signal; means coupled to an electrical supply input of the oscillator such that they generate a voltage for supplying the oscillator at the frequency of the frequency modulated periodic signal.

Abstract: A method for measuring, using a radar or sonar, the velocity with respect to the ground of a carrier moving parallel to the ground, includes the following steps: a) orienting the line of sight of the radar or sonar toward the ground; b) emitting a plurality of radar or sonar signals (P1-PN) that are directed toward the ground, and acquiring respective echo signals (E1-EN); c) processing the acquired echo signals so as to obtain, for one or more echo delay values, a corresponding Doppler spectrum; d) for the or at least one the echo delay value, determining a high cut-off frequency of the corresponding Doppler spectrum; and e) computing the velocity of the carrier with respect to the ground on the basis of the one or more high cut-off frequencies. A system allowing such a method to be implemented.

Abstract: The invention concerns a digital delay locked loop comprising: first and second digitally controllable delay lines (202B, 204B) coupled in series with each other, each comprising a lead portion (214, 218) and a lag portion (216, 220), the first digitally controllable delay line receiving a reference timing signal (TREF) and the second digitally controllable delay line outputting a delayed timing signal (TREF); and a time to digital converter (212) configured to evaluate a phase difference between the reference signal (TREF) and the delayed timing signal (TREF?) and to generate a first control signal (DLEAD_[0:n]) for controlling said lead portions (214, 218) or a second control signal (DLAG[0:n]) for controlling said lag portions (216, 220) based on the sign and magnitude of the phase difference.

Abstract: The invention concerns a digital delay locked loop comprising: first and second digitally controllable delay lines (202B, 204B) coupled in series with each other, each comprising a lead portion (214, 218) and a lag portion (216, 220), the first digitally controllable delay line receiving a reference timing signal (TREF) and the second digitally controllable delay line outputting a delayed timing signal (TREF); and a time to digital converter (212) configured to evaluate a phase difference between the reference signal (TREF) and the delayed timing signal (TREF?) and to generate a first control signal (DLEAD_[0:n]) for controlling said lead portions (214, 218) or a second control signal (DLAG[0:n]) for controlling said lag portions (216, 220) based on the sign and magnitude of the phase difference.

Abstract: A method for automatically focusing a camera comprising an image sensor, at least one lens configured to project an image onto the sensor and an actuator configured to modify a focusing parameter of the lens, comprises: a first phase of controlling the actuator in an open loop so the focusing parameter successively takes a plurality of predefined values, images being acquired for each value of the focusing parameter and a sharpness indicator being calculated on the basis of each image; and a second phase of controlling the actuator in a closed loop to maximize the sharpness indicator, the second closed-loop control phase being implemented by making use of a control law and starting conditions determined on the basis of the sharpness indicators calculated during the first phase. A system for automatically focusing a camera for implementing the method, and a camera equipped with such a system is provided.

Abstract: A design method for a phase-locked loop comprises: a controlled-frequency oscillator; a phase comparator, to determine a phase difference between an output signal of the controlled-frequency oscillator and a reference signal; a corrector to receive as input a signal representative of the phase difference and to generate at its output a first correction signal; at least one second corrector, to receive as input a signal representative of or affected by a phase noise of the reference signal or of the output signal of the controlled-frequency oscillator and to generate at its output a second correction signal; and a circuit for generating a slaving signal for the controlled-frequency oscillator on the basis of the first and second correction signals; the method using the H-infinity method. Method for fabricating such a loop comprising a design step implementing this method. Phase-locked loop thus obtained.

Abstract: A method for automatically focusing a camera comprising an image sensor, at least one lens configured to project an image onto the sensor and an actuator configured to modify a focusing parameter of the lens, comprises: a first phase of controlling the actuator in an open loop so the focusing parameter successively takes a plurality of predefined values, images being acquired for each value of the focusing parameter and a sharpness indicator being calculated on the basis of each image; and a second phase of controlling the actuator in a closed loop to maximize the sharpness indicator, the second closed-loop control phase being implemented by making use of a control law and starting conditions determined on the basis of the sharpness indicators calculated during the first phase. A system for automatically focusing a camera for implementing the method, and a camera equipped with such a system is provided.

Abstract: A design method for a phase-locked loop comprises: a controlled-frequency oscillator; a phase comparator, to determine a phase difference between an output signal of the controlled-frequency oscillator and a reference signal; a corrector to receive as input a signal representative of the phase difference and to generate at its output a first correction signal; at least one second corrector, to receive as input a signal representative of or affected by a phase noise of the reference signal or of the output signal of the controlled-frequency oscillator and to generate at its output a second correction signal; and a circuit for generating a slaving signal for the controlled-frequency oscillator on the basis of the first and second correction signals; the method using the H-infinity method. Method for fabricating such a loop comprising a design step implementing this method. Phase-locked loop thus obtained.

Abstract: An oscillation detector having an RF oscillator configured to be synchronized with a first frequency and a comparator for distinguishing the synchronized state from the non-synchronized state of the radiofrequency oscillator on the basis of an oscillating signal produced by the radiofrequency oscillator and indicating the presence of oscillations in a frequency band around the first frequency in response to identifying the synchronized state and, in alternation, indicating the absence of oscillations in this frequency band otherwise.

Abstract: An oscillator including two groups of elementary junctions having giant magnetoresistance effect traversed by electric currents, the junctions of each of the two groups being in series and energized by respective main currents and the voltages across the terminals of the groups being added together to provide a voltage on an output of the oscillating circuit. The voltage across the terminals of one or more junctions of a first group is applied to a first input of a phase comparator and the voltage across the terminals of one or more junctions of the other group is applied to another input of the phase comparator, the phase comparator providing on two outputs secondary currents of the same amplitude and of opposite signs, which are dependent on the mean phase difference between the voltages applied to the inputs, the secondary currents each being added to a respective main current.

Abstract: An oscillation detector having an RF oscillator configured to be synchronized with a first frequency and a comparator for distinguishing the synchronized state from the non-synchronized state of the radiofrequency oscillator on the basis of an oscillating signal produced by the radiofrequency oscillator and indicating the presence of oscillations in a frequency band around the first frequency in response to identifying the synchronized state and, in alternation, indicating the absence of oscillations in this frequency band otherwise.

Abstract: An oscillator including two groups of elementary junctions having giant magnetoresistance effect traversed by electric currents, the junctions of each of the two groups being in series and energized by respective main currents and the voltages across the terminals of the groups being added together to provide a voltage on an output of the oscillating circuit. The voltage across the terminals of one or more junctions of a first group is applied to a first input of a phase comparator and the voltage across the terminals of one or more junctions of the other group is applied to another input of the phase comparator, the phase comparator providing on two outputs secondary currents of the same amplitude and of opposite signs, which are dependent on the mean phase difference between the voltages applied to the inputs, the secondary currents each being added to a respective main current.