Y.T. Karmanov - D.Sc. (Eng.), Professor, Director of Institute of Digital Processing Systems and Information Protection of South Ural State University (National Research University). E-mail: ea@drts.susu.ac.ru
S.V. Povalyaev - Post-graduate Student, Department of Information Communication Technologies of South Ural State University (National Research University). E-mail: svp.drts@gmail.com

In this article are given the results of dependency characteristics of the chirp signals synthesized by technology DDS from the parameters of the DDS-synthesizer. The dependences of the ambiguity function of the chirp signal synthesized by the method of direct digital synthesis (DDS) when using it as a probe chirp signal in pulse radio range finder from the parameters of the DDS-synthesizer are received. It is shown that when forming a probing chirp signal on the DDS technology in pulse radio range finders needs to apply DDS synthesizers with switching time of frequencies much smaller than the duration of the synthesized chirp signal. In this case the characteristics of the pulse radio range finder close to characteristics of the radio range finder with an ideal probing chirps signal are implemented. Defined relationships between the parameters of a DDS synthesizer and frequency spectrum of beat signal in case of its use as a probing signal in the frequency radio range finders. It is established that in case of a choice timing of switching frequencies in a DDS synthesizer much smaller the period of oscillations of the beat signal with the greatest possible frequency of beat, characteristics of the frequency radio range finder insignificantly differ from the characteristics of radio range finder with an ideal chirp signal.