摘要:
A device processes a received radio signal. Circuitry formulates voltage samples of the radio signal. Analog processing of those samples is performed. Then, digital processing is performed on the output of the analog processing. The circuitry for formulating voltage samples is configured to ensure a processing of the samples prior to the digital processing.
摘要:
A device processes a received radio signal. Circuitry formulates voltage samples of the radio signal. Analog processing of those samples is performed. Then, digital processing is performed on the output of the analog processing. The circuitry for formulating voltage samples is configured to ensure a processing of the samples prior to the digital processing.
摘要:
A distributed oscillator includes an odd number of serially connected amplifying elements. An output of a last amplifying element is looped back to an input of a first amplifying element via a first transmission line. The oscillator oscillates at a first frequency f1. The oscillator further includes circuitry for injecting a control signal onto the input of the first amplifying element. The control signal has a second frequency f2 which is a sub-multiple of the first frequency f1.
摘要:
Device for generating a signal of parametrizable frequency comprising a phase locked loop including a generator of a reference signal, a phase-frequency comparator comprising a first input for receiving the reference signal, an oscillator controlled on the basis of the result output by the phase-frequency comparator, a fractional divider coupled between an output of the oscillator and a second input of the phase-frequency comparator, and a selector selectively linking an input of the oscillator either with an input of the generator, or with the output of the oscillator as a function of the multiplication ratio of the fractional divider.
摘要:
Device for generating a signal of parametrizable frequency comprising a phase locked loop including a generator of a reference signal, a phase-frequency comparator comprising a first input for receiving the reference signal, an oscillator controlled on the basis of the result output by the phase-frequency comparator, a fractional divider coupled between an output of the oscillator and a second input of the phase-frequency comparator, and a selector selectively linking an input of the oscillator either with an input of the generator, or with the output of the oscillator as a function of the multiplication ratio of the fractional divider.
摘要:
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.
摘要:
Continuous time analogue/digital converter, comprising a sigma delta modulator (MSD1) configured to receive an analogue input signal (x(t)) and comprising high-pass filtering means (MF) the chopping frequency of which is equal to half of the sampling frequency (Fs) of the quantization means (QTZ) of the modulator (MSD1).
摘要:
A phase locked loop includes a controlled oscillator for delivering an output signal at a determined output frequency, and a variable frequency divider for converting the output signal into a signal at divided frequency. The PLL is termed composite in that it includes at least one first loop having a loop filter for generating a first control signal for the oscillator on the basis of the signal at divided frequency, and a second loop having a loop filter, different from the loop filter of the first loop, for generating, on the basis of the signal at divided frequency, a second signal for additional control of the oscillator. The loop filter of the first loop and the loop filter of the second loop have different respective cutoff frequencies. The passband of the first loop, can be adapted to ensure the convergence and the stability of the PLL, while the second loop can afford extra passband increasing the speed of adaptation of the PLL in case of modification of the value of a preset for the output frequency.
摘要:
Continuous time analogue/digital converter, comprising a sigma delta modulator (MSD1) configured to receive an analogue input signal (x(t)) and comprising high-pass filtering means (MF) the chopping frequency of which is equal to half of the sampling frequency (Fs) of the quantization means (QTZ) of the modulator (MSD1).
摘要:
A method is for reducing a DC component of an input signal transposed into baseband and being generated by a first frequency transposition stage starting from an initial signal and from a transposition signal. The method includes amplifying the transposed input signal in a first amplifier. The first amplifier receives at a DC offset compensation input, a compensation signal extracted from an output signal of a second amplifier subjected to a compensation of a offset DC voltage of the second amplifier. The method also included alternating between receiving at an input of the second amplifier, a first auxiliary signal from an auto-transposition of a transposition signal in a second frequency transposition stage and a second auxiliary signal from a transposition of the initial signal in the second frequency transposition stage with the transposition signal.