Device for the automatic linearisation of the frequency-control signal characteristic of a frequency-modulated oscillator with variable frequency

摘要

the device includes a phase-locked loop (2) with an entry which is applied to set the output of a variable frequency oscillator (5) is frequency modulated.the bandwidth of the loop (2) is adjusted to obtain a filtered signal at its output frequency corresponding to the frequency modulated signal applied to the input of instruction is free of.frequency of modulation.a phase demodulator (3) coupled to the input of the instruction loop (2) and at the exit of the loop (2) provides a signal corresponding to the modulation index of the signal provided by the oscillator(5).this signal is compared with a reference signal by a comparator circuit (4) which delivers a control signal to the means of adjustment (7), the amplitude of the modulating signal applied to the gate ofthe oscillator (5) in order to adjust continuously the index of modulation of the frequency modulated signal produced at the output of the oscillator (5).the value of the desired modulation index corresponding to the reference signal.;ground application: microwave frequency diversity.