METHOD FOR OBTAINING RADIO FREQUENCY SIGNAL WITH REDUCED LEVEL OF BY-SIDE DISCRETE COMPONENTS Russian patent published in 2018 - IPC H03B1/04 H03L7/16 

FIELD: radio engineering.

SUBSTANCE: invention relates to synthesizers based on phase-locked-loop frequency control. Method for obtaining a radio frequency signal includes clocking the first chip of direct digital synthesis using a signal of frequency F_syncr for obtaining the reference signal F_dds1=α₁F_syncr; branching a part of the signal F_out, obtained at the output of a voltage-controlled generator, into the negative feedback loop for its frequency conversion, which is carried out with the help of a second direct digital synthesis chip, clocking it with a signal of frequency F_out-DF_syncr, to obtain on its output a signal of frequency F_dds2=α₂(F_out-DF_syncr), where α₁ and α₂ – are the coefficients that are chosen, based on the condition of their non-occurrence in the predefined "forbidden" ranges of values, whose conversion in the first and second direct digital synthesis chips respectively results in an output signal with side discrete components of amplitude A_n^out above permissible A_additional, where n is the harmonic number of the secondary discrete component of the output signal.

EFFECT: technical result consists in reducing the level of spurious discrete components of the output radio frequency signal while maintaining a sufficiently low level of phase noise.

1 cl, 5 dwg