Patent ID: 8044725

Claim:
A signal generator comprising: a DDS-signal source that is configured to operate according to the principle of direct digital synthesis (DDS), wherein the DDS-signal source comprises a DDS module, and a multiplier configured to generate a pulse modulation by multiplying a digital output word of the DDS module by a digital modulation word; and a PLL signal synthesizer that is configured to operate according to the principle of phase locked loop (PLL) using an output signal from the DDS-signal source as a reference signal, wherein the signal generator is configured to generate signals of a wide range of frequencies from a few kHz up to microwave frequencies, wherein the output signal from the DDS-signal source is of a frequency range comprising a portion of an overall frequency range of the signal generator, and wherein, if a desired output frequency of the signal generator is within the frequency range of the output signal from the DDS-signal source, the signal generator is configured to output the output signal from the DDS-signal source as an output of the signal generator, without further frequency division or mixing, irrespective of the state of the PLL signal synthesizer.