Phase-locked loop with multiple degrees of freedom and its design and fabrication method

A method of designing a phase-locked loop, the phase-looked loop being of the type comprising:

• a controlled-frequency oscillator;
• a phase comparator, configured to determine a phase difference between an output signal of the said controlled-frequency oscillator and a reference signal;
• a first corrector, configured to receive as input a signal representative of the said phase difference and to generate at its output a first correction signal;
• at least one second corrector, configured to receive as input a signal representative of or affected by a phase noise of the said reference signal or of the said output signal of the said controlled-frequency oscillator and to generate at its output a second correction signal;
• and
• a circuit for generating a slaving signal for the said controlled-frequency oscillator from the said first and second correction signals;
• the said method comprising a step of determining transfer functions of the said correctors allowing rejection, in one and the same frequency band, the phase noise of
• the said reference signal and the phase noise of the said output signal of the said controlled-frequency oscillator, and wherein said step is implemented, by means of a computer, by applying the H∞ method utilizing:
• at input, a first weighting function for a phase noise of the said controlled-frequency oscillator and a second weighting function for a phase noise of a reference signal, and which are determined on the basis of nominal power spectral densities of the said noise;
• and
• at output, at least one third weighting function for a phase noise of an output signal of the phase-lock loop or of an error in tracking the said reference signal, determined on the basis of a phase noise power spectral density template of the said output signal having to be complied with.