The Generation and Realization of Nonlinear Frequency Modulation Signal Based on DDS
Fenglin Li · Guidance and Fuze · 2007
The structure of the hardware system and the software realization approach to generate NLFM signal based on Direct Digital Synthesis(DDS) is given and detailed in this paper.The hardware system is an arbitrary complicated waveform generator based on DDS.By the programme of FPGA on it,the waveform generator can generate all kinds of signal with different interval,different bandwidth and flexible modulation mode under 100 MHz,so this generator is all-purposed.The software approach to produce the NLFM signal is using the method of linear fitting subsection,and it can control all kinds of signal parameter to generate the NLFM signal with different interval and different bandwidth.The test result shows that the method has the merits of low phase noise,low sidelobe in pulse compression,simple in realization and so on.