METHOD AND DEVICE FOR FREQUENCY MODULATION Russian patent published in 1998 - IPC

FIELD: radio engineering; transmitting devices. SUBSTANCE: high-stability frequency standard 1 functions to regulate frequency of variable-frequency oscillators 2₁ and 2₂ by means of PLL rings incorporating respective phase detectors 3₁ and 3₂ and low-frequency filters 4₁ and 4₂. Frequency of first variable-frequency oscillator 4₁ is varied obeying modulating signal law S(t), that of second oscillator, obeying inverting signal law S(t). Signal picked off first oscillator 4₁ is multiplied n times in multiplier 6₁ and that taken off second oscillator 4₂ is multiplied (n-1) times in multiplier 6₂. Signals taken off multipliers 6₁ and 6₂ are supplied to mixer 7 and then differential signal is discriminated by band filter 8. EFFECT: enlarged frequency variation range ensuring improved frequency stability. 2 cl, 2 dwg