Arrangement for reducing the spurious spectral lines contained in a digital frequency synthesizer output signal

摘要

The invention relates to an arrangement for reducing the spurious spectral lines contained in a digital frequency synthesizer (10) output signal, receiving, on the one hand, a clock signal (E) originating from a modulator (11) and supplying an output signal (Sdds) at a pure frequency (FS) modulated by spurious frequencies. The arrangement includes a frequency demodulator (13) receiving the output signal from the synthesizer (10) and supplying a correction signal, the amplitude (Vm) of which is a function of the frequency excursion of the output signal (Sdds) of the synthesizer (10), this correction signal being applied to the modulator (11) so that it modulates the signal applied to the synthesizer (10) in phase opposition with respect to the spurious modulation, so as to suppress this spurious modulation. IMAGE