宽带线性调频信号产生及补偿技术研究

Generation of Wideband LFM and Its Compensation Techniques

线性调频信号的基带信号产生方法主要有DDS和DDWS两种.基于FPGA并行理论和高速DAC架构的DDWS方法,产生L波段、带宽125MHz基带信号,并结合倍频链的方法设计与实现了500MHz大带宽线性调频信号产生系统.基于滤波器的预失真补偿原理提出对系统进行幅相补偿,给出了具体实现步骤,提高了线性调频信号脉压主副瓣比.该技术在实际应用中性能优良,工作可靠.

The generation methods of baseband signals for linear frequency modulation signals are mainly classified as DDS and DDWS. This paper focuses on generation of the baseband signals with bandwidth of 125MHz in L band, based on FPGA parallel theory and DDWS method for high-speed DAC architecture, and implements the generation system of LFM signals with 500MHz bandwidth, by combining the design scheme of double-frequency link. It is suggested that the amplitude-phase compensation can be performed on the system in terms of the principles of pre-distortion compensation of filters. And the concrete implementation steps are given in this paper, which improves the ratio of main lobe to side lobes of pulse voltages of LFM signals. This proposed technique is of better performance and reliable operation for application.