METHOD OF GENERATING OUTPUT FREQUENCY OF DIRECT SYNTHESIS DIGITAL SYNTHESISER Russian patent published in 2014 - IPC H03B1/04 H03L7/16 

FIELD: radio engineering, communication.

SUBSTANCE: method of generating output frequency of a direct synthesis digital synthesiser involves calculating a frequency code in accordance with the required output frequency value; recording in a frequency register and transmitting the frequency code to a phase accumulator; if the calculated value of the frequency code is a fraction, calculating a first frequency code corresponding to the initial frequency code rounded off to a whole number and the fractional part of the initial frequency code; selecting a second frequency code differing by one from the first frequency code, and recording in the frequency register; alternately reading from the frequency register the first and second frequency codes with periodicity defined by the fractional part of the initial frequency code; the frequency code comes from the frequency register and the phase accumulator; the phase accumulator calculates an address which is input into the ROM of a phase register; the phase register calculates the instantaneous value of the output signal in digital form, which is transmitted to a digital-to-analogue converter and is converted to a corresponding signal value in analogue form.

EFFECT: low level of secondary discrete components of the output signal.

2 cl, 2 dwg