Abstract: A radiofrequency unit comprising a first dielectric substrate supporting a first conductive antenna layer; a second dielectric substrate supporting circuit elements connected or coupled to ground formed in a second conductive layer, and comprising a radiofrequency antenna line; and a third screen conductive layer arranged between the first and second substrates, provided with a slot to couple the antenna line to the antenna layer, this conductive layer being floating; in which the thickness and the nature of the second substrate are chosen by taking into account the surface of said circuit elements for the screen layer to be coupled to ground by a capacitor forming a short-circuit for radiofrequencies.

Abstract: The frequency synthesizer includes a phase-locked loop (PLL). The PLL includes an oscillator controlled to deliver an output signal at a predefined output frequency, a variable frequency divider to convert the output signal into a divided-frequency signal, a phase comparator to produce a signal measuring a phase difference between the divided-frequency signal and a reference signal at a reference frequency, and a loop filter to control the oscillator on the basis of the measurement signal. To increase the speed of convergence of the synthesizer if the set point is changed, the loop filter of the PLL is a fractional, i.e. non-integer, order low-pass filter.

Abstract: A signal modulation device comprises a delta-sigma modulator disposed for transforming an amplitude-modulation signal in baseband into a pulse signal. It also comprises a phase modulator receiving, at its input, analogue phase-modulation signals in baseband. The pulse signal is mixed with carrier signals upstream of the phase modulator. The modulation device is designed to form an input stage of a transmitter.

Abstract: A heterodyne receiving circuit for a digital communication system including a first band pass filter receiving a signal from an antenna, an amplifying circuit and a second narrow band pass filter for selecting one particular channel within a band of frequencies. The two filters are carried out with integrated BAW-type tunable resonators which can be adjusted, respectively, by a first electrical signal and a second electrical signal generated by two PLL-type frequency control loops. The second frequency control loop has a variable division factor for the purpose of selecting one particular channel within said band of frequencies. In addition, the receiving circuit includes a mixer for mixing the signal generated at the output of said second filter with a local oscillation frequency in order to produce an intermediate frequency. The division factor is controlled by a digital processing of the intermediate frequency.

Abstract: An integrated electronic circuit comprises at least first and second variable resonator elements that can be tuned by means of an electric signal (Vtune) and that are arranged on the same silicon substrate, and that are respectively integrated into a Master circuit and a Slave circuit. Each resonator element is associated with a first inductive partner element set in the vicinity of the resonant and antiresonant frequencies; and with a second capacitive partner element, at least one of said partner elements being adjustable by means of said electric signal (Vtune). Controlling both partner elements could be done either by means of an adjustable capacitor, as a varactor, or by means of an inductor, passive or active, fixed or variable.

Abstract: An embodiment of an electronic signal amplifier comprises a power source, an input inductor, an output inductor and one or more branches connected in parallel between the terminals of the power source. Each branch comprises a transistor having a control electrode connected to an intermediate terminal of the input inductor, a first main electrode connected to a first terminal of the power source, and a second main electrode connected to a second terminal of the power source via a capacitor. The second main electrode of each transistor of a branch is also connected to an intermediate terminal of the output inductor.

Abstract: A phase-locked loop that can be integrated into a semiconductor product comprises: a phase comparator having a first input, a second input and an output, said first input receiving a reference frequency; a low-pass filter having an input connected to said output of said phase comparator and having an output generating an electric control signal (Vtune); an oscillating circuit generating a predefined frequency signal to be controlled; a dividing block having an input receiving the oscillating signal and an output connected to said second input of said phase comparator. The oscillating circuit comprises a BAW-type acoustic resonator having first and second resonant frequencies and associated with a first inductive partner element to cancel out said second resonant frequency and with a second capacitive partner element for regulating said first resonant frequency, said at least first resonator component being adjusted via said electric signal (Vtune).

Abstract: The invention relates to a transconductor, comprising means for automatic selection of a nonlinear function of class A or a linear function of class AB from an input signal for processing and for automatic adjustment of the current drawn from a supply to a level necessary for the functioning thereof.

Abstract: An electronic circuit comprises a resonator meant to be integrated into a semiconductor product including a resonator having first and second resonant frequencies. The electronic circuit comprises: a first inductive partner element for canceling out said second resonant frequency, said partner element having a quality coefficient QI (f) having a first value in a predetermined frequency band and a second value outside said frequency band; a second capacitive partner element for adjusting tuning of said resonator to said first frequency.

Abstract: An acoustic resonator circuit to be integrated into a semiconductor product including: a resonator comprising first and second resonant frequencies; an inductive resistor tuned to said second resonant frequency so as to cancel the latter and to allow tuning of the resonator to said first resonant frequency; an tunable capacitive tuning element allowing to tune the resonator to said first frequency. A method is also provided for manufacturing an integrated circuit comprising an acoustic component allowing sufficient control of resonator characteristics.

Abstract: A differential mixer including at least two input/output stages, each stage including two identical branches, each branch of one of the two stages including at least two bipolar transistors the bases of which define a first pair of input/output terminals of the stage and are connected to a same D.C. current source individually by a respective isolating resistor; the collectors of which define a second pair of input/output terminals of the stage which forms a pair of input/output terminals of another stage of the mixer; and the emitters of which are individually connected to a low voltage reference line by a respective degenerative impedance.

Abstract: A structure of protection of an area of a semiconductor wafer including a lightly-doped substrate of a first conductivity type against high-frequency noise likely to be injected from components formed in the upper portion of a second area of the wafer. The structure includes a very heavily-doped wall of the first conductivity type having substantially the depth of the upper portion. The wall is divided into segments, each of which is connected to a ground plane.

Abstract: An amplifier device with gain switching includes an amplifier, and a configurable load circuit including an inductive element. The configurable load circuit is capable of exhibiting two configurations having two different impedance values. A controllable switch is connected between the amplifier and the load circuit to select one of the two configurations of the load circuit. The load circuit includes two insulated-gate field effect load transistors connected in series, and which operate in a triode mode. The inductive element is connected in parallel with the pair of load transistors, and between a power supply terminal and the switching circuit.

Abstract: A radiofrequency unit comprising a first dielectric substrate supporting a first conductive antenna layer; a second dielectric substrate supporting circuit elements connected or coupled to ground formed in a second conductive layer, and comprising a radiofrequency antenna line; and a third screen conductive layer arranged between the first and second substrates, provided with a slot to couple the antenna line to the antenna layer, this conductive layer being floating; in which the thickness and the nature of the second substrate are chosen by taking into account the surface of said circuit elements for the screen layer to be coupled to ground by a capacitor forming a short-circuit for radiofrequencies.

Abstract: A variable phase-shifting circuit comprises an input for receiving an input signal having a specified oscillation frequency, an output for delivering an output signal having the same oscillation frequency and having a variable phase shift with respect to the input signal, and at least a control input. The control input receives a control signal that controls the phase shift of the output signal with respect to the said input signal. The circuit includes a synchronized oscillator with a synchronization input coupled to the input of the phase-shifting circuit for receiving the input signal, at least an output coupled to the output of the phase-shifting circuit for delivering the output signal. The synchronized oscillator has a variable free-running oscillation frequency which is controlled by the control signal. Application is proposed to phase interpolation and digital frequency synthesis.

Abstract: The invention concerns a structure for protecting a first zone of a semiconductor wafer comprising a substrate (11) having a first type of conductivity against high frequency disturbances liable to be injected from components formed in the upper part of a second zone of the wafer, comprising a highly-doped wall of the first type of conductivity having substantially the depth of said upper part. The invention is characterised in that said wall is divided into three highly-doped strips (21) of the first type of conductivity separated and enclosed by moderately-doped intermediate strips (23) of the first type of conductivity, the distance between the highly-doped end strips being of the order of magnitude of the substrate thickness.

Abstract: The amplifier includes an input amplifier stage, an output amplifier stage cascode-connected with the input amplifier stage, and a load stage connected to the output stage. The load stage includes a plurality of circuits each including a capacitive component and an inductive component having a Q greater than 10, and having respective different resonant frequencies. All the gain curves respectively associated with all the circuits have, to within a stated tolerance, the same maximum gain value at the resonant frequencies. The gain curves respectively associated with two circuits having respective immediately adjacent resonant frequencies overlap below a threshold 3 dB, to within a stated tolerance, below the maximum gain value.

Abstract: A head of transmission-reception of a high-frequency signal made in the form of an integrated circuit including a transmit amplifier and a receive amplifier. The transmit terminal of the transmit amplifier and the receive terminal of the receive amplifier are interconnected in a common transmit/receive terminal. The head includes means for selecting one of the amplifiers and means for placing the other amplifier in a high impedance state, as seen from the transmit/receive terminal.

Abstract: A differential mixer including at least two input/output stages, each stage including two identical branches, each branch of one of the two stages including at least two bipolar transistors the bases of which define a first pair of input/output terminals of the stage and are connected to a same D.C. current source individually by a respective isolating resistor; the collectors of which define a second pair of input/output terminals of the stage which forms a pair of input/output terminals of another stage of the mixer; and the emitters of which are individually connected to a low voltage reference line by a respective degenerative impedance.

Abstract: An amplifier device with gain switching includes an amplifier, and a configurable load circuit including an inductive element. The configurable load circuit is capable of exhibiting two configurations having two different impedance values. A controllable switch is connected between the amplifier and the load circuit to select one of the two configurations of the load circuit. The load circuit includes two insulated-gate field effect load transistors connected in series, and which operate in a triode mode. The inductive element is connected in parallel with the pair of load transistors, and between a power supply terminal and the switching circuit.