I.V. Ryabov1, T.S. Bukanova2, N.V. Degtyarev3

1-3 Volga State University of Technology (Yoshkar-Ola, Russia)

1 ryabov22@mail.ru

Problem statement. This paper presents the design principles and structural and circuit solutions of direct digital synthesizers, based on the direct digital synthesis of frequencies and signals. The structural and circuit diagrams of a direct digital synthesizer of frequency-modulated signals, capable of synthesizing signals with amplitude, frequency, and phase modulation in the frequency range from 0.001 to 200 MHz are presented.

The purpose of this work is to improve the performance and linearity of the frequency variation law for generating complex signals as well as to expand the functionality of the direct digital synthesizers.

Results. The proposed direct digital synthesizer of complex broadband signals enables the synthesis of signals with frequency, phase, and amplitude modulation, while the control of the direct digital synthesizer is accomplished by a user-friendly digital interface.

This direct digital synthesizer can be used as an exciter of transmitters and heterodynes of receivers of modern adaptive HF and VHF communication systems with pseudo-random frequency hopping, which will increase the noise immunity and reliability of the communication session. It can also be used in a hardware and software radio complex for remote sensing of the Earth's atmosphere to obtain amplitude-frequency and distance-frequency characteristics of radio lines.

Practical value. The proposed direct digital synthesizer structure has high frequency variation linearity with a step size of less than 0.001 Hz. This direct digital synthesizer can be used as an exciter for transmitters and receiver heterodynes in modern adaptive HF and VHF communication systems.

Ryabov I.V., Bukanova T.S., Degtyarev N.V. Direct digital synthesizer with high degree of frequency variation law linearity // Radiotekhnika. 2026. V. 90. № 6. P. 40−49. DOI: https://doi.org/10.18127/j00338486-202606-04

1. Yampurin N.P., Boloznev V.V., Safronov E.V., Zhalnin E.B. Formirovanie precizionnyh chastot i signalov: ucheb. poso-bie. Nizhnij Novgorod: Nizhegorodskij gos. tekhnich. un-t. 2003.187 s. (in Russian).
2. Belov L.A. Radioelektronika: Formirovanie stabil'nyh chastot i signalov: uchebnik dlya bakalavriata i magistratury. Izd. 2-e. M.: Izd-vo «Yurajt». 2018. 242 s. (in Russian).
3. Ryabov I.V. Pryamoj cifrovoj sintez signalov dlya zadach radiolokacii, navigacii i svyazi. Joshkar-Ola: PGTU. 2016. 151 s. (in Russian).
4. Ryabov I.V., Tolmachev S.V., Chernov D.A. Cifrovoj vychislitel'nyj sintezator slozhnyh shirokopolosnyh signalov. Pribory i tekhnika eksperimenta. 2014. № 4. S. 13-19 (in Russian).
5. Ryabov I.V. Digital synthesizers of frequency-modulated signals. Instruments and Experimental Techniques. 2001. V. 44. № 2. P. 62-68 (in Russian).
6. Patent № 2149503 (RF), MKI N03V 19/00. Cifrovoj sintezator chastot. Ryabov I.V., Ryabov V.I., Golub D.V. Zayavl. 13.04.1999. Opubl. 20.05.2000. Byul. № 13. 5 s. (in Russian).
7. Patent № 2358384 (RF), MPK N03L 7/18. Cifrovoj sintezator chastotno- i fazomodulirovannyh signalov. Ryabov I.V., Yur'ev P.M. Zayavl. 31.05.2007. Opubl. 10.06.2009. Byul. № 18. 6 s. (in Russian).
8. Vankka, J. Direct digital synthesizers theory and application. Proc. Int. Symp. Circuits and Systems ISCAS’03. 2006. 210 p.
9. Wang C.-C., Huang J.-M., Tseng Y.-L. Phase-adjustable pipelining ROM-less direct digital frequency synthesizer with a 41.66-MHz oUTPUT fREQUENCY. Circuits and Systems II: Express Briefs. IEEE Transactions. 2006. V. 53. P. 1143-1147.
10. Ryabov I.V., Tolmachev S.V. Apparatno-programmnyj kompleks dlya organizacii svyazi v polyarnyh shirotah. Radiotekhnicheskie i telekommunikacionnye sistemy. 2020. № 3. S. 58-63 (in Russian).
11. Ryabov I.V., Bukanova T.S., Makarov A.E., Alekseev N.O. Cifrovye sintezatory chastotno-modulirovannyh signalov dlya telekommunikacionnyh sistem. Radiotekhnicheskie i telekommunikacionnye sistemy. 2024. № 3. S. 73-79 (in Russian).