METHOD OF PRODUCING RADIO-FREQUENCY SIGNAL Russian patent published in 2016 - IPC H03B1/04 H03L7/16 

FIELD: communication.

SUBSTANCE: invention relates to synthesizers based on phase automatic frequency control loop (PLL). For production of radio-frequency signal, signal of frequency F_sync is obtained, and with this signal first microcircuit of direct digital synthesis is clocked in order to obtain reference signal with frequency F_dds1=α₁F_sync. Phases and frequencies of reference and synchronised signals are compared to generate analogue voltage proportional to phase and/or frequency mismatch, voltage obtained is filtered at low frequency, and this voltage is supplied to voltage-controlled generator, in order to produce at its output signal with frequency F_out. Part of obtained signal is derived into negative feedback loop for its frequency conversion with subsequent supply of converted signal as synchronised one to phase-frequency detector. Frequency transformation is performed by means of second microcircuit of direct digital synthesis, which is clocked with signal of frequency F_out-DF_sync, obtained by mixing of signals with frequencies F_out and DF_sync with further separation of differential component in order to produce signal with frequency F_dds2=α₂(F_out-DF_sync) at its output, where D is frequency division factor for clocking first microcircuit of direct digital synthesis. Note here that factors α₁ and α₂ are selected based on not fitting into predetermined "prohibited" values fields.

EFFECT: technical result consists in reduction of level of unwanted discrete components in output radio-frequency signal while reducing level of phase noise.

2 cl, 3 dwg