LOW-NOISE FREQUENCY SYNTHESIZER DESIGN WITH LOW LEVEL OF SIDE SPECTRAL COMPONENTS Russian patent published in 2025 - IPC H03L7/16 

FIELD: radio engineering.

SUBSTANCE: invention relates to radio engineering and can be used as a source of microwave oscillations in radio measuring equipment. Frequency synthesizer comprises a reference generator, a coarse-grid frequency synthesizer, a fine-grid frequency synthesizer, a phase-locked loop (PLL) summing ring and is characterized by the implementation of a fine grid frequency synthesizer in the form of a connection of a looped mixer and a fractional PLL synthesizer, which form a feedback circuit with frequency down conversion with a frequency divider with a variable division factor installed at the output of the fractional PLL synthesizer, as well as connection between synthesizer of frequencies of coarse grid and summing ring of PLL of additional ring of PLL of synthesizer of frequencies of non-uniform grid, made with mixer in feedback circuit.

EFFECT: reducing the level of side spectral components in the output signal while maintaining a low level of phase noise and a small frequency tuning step.

1 cl, 4 dwg