摘要
介绍了一种基于直接数字频率合成器(DDS)的非线性调频信号的硬件系统结构和软件实现方法。该信号的硬件系统是基于DDS的任意复杂波形产生器,通过对波形产生器上的FPGA编程,可以产生100 MHz以下时宽、带宽、调制方式灵活可控的各种信号,因此该波形产生器具有一定的通用性。该信号的软件实现方法是采用分段折线拟合来近似产生NLFM信号,通过FPGA控制DDS输出信号的各项参数指标,可以方便地用该波形产生器实现不同时宽、带宽NLFM信号的产生。实验证明本文方法产生的NLFM信号具有相噪低、脉压旁瓣低、实现简捷等诸多优点。
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.
出处
《制导与引信》
2007年第2期47-52,共6页
Guidance & Fuze
关键词
非线性调频
数字频率合成
脉冲压缩
nonlinear frequency modulation
digital frequency synthesizer
pulse compression
