Direct digital frequency synthesis enabling spur elimination

The invention, usually connected with such part method for improving, for generating clearly, profile of delicate adjusting, at least partially provided with the digital method. A of the invention, provides a erroneous generator, for generating a digital signal; the signal with manifested frequency error between the digital frequencies and an frequencies. The frequency error hood is digital integrated, generating a digital signal to manifest the phase error. The erroneous generator a can be a PLL, the analogue frequency came from a PLL VCO the output signal. Time direct-frequency circuit is connected in digital upper end is the output A signal. Further through a or a wire auxiliary, and direct-frequency modulation circuit and or a wire end of the correction auxiliary, the modulation the cover is separated from the loop bandwidth limiting. The, A loop bandwidth made of special very water-blocking, capable of clutter (convex) is made of low layer (DDS and techniques associated). A PLL loop filter capable of the digital form. A digital loop filter usually needs is high resolution DAC. The invention elaborated multiple technologies can be used to reduce to the DAC resolution requirement.