为了方便宽带雷达信号产生,同时避免因采用传统倍频方法引起的幅相失真,文中提出了一种基于多路并行直接数字频率合成(DDS)的宽带信号产生技术。该技术基于现场可编程门阵列设计一种多路并行DDS结构,通过数字中频直接产生的方式生成多路可变相差的线性调频信号;同时,设计相位补偿算法对各路信号进行相位补偿;最后,经高速数模转换器采样将多路信号合成为一路宽带可调波形输出。仿真和实验结果表明:该方法能输出高中频和大瞬时带宽信号;同时,还具有结构简单、频率分辨率高和频率转换速度快等优点。

A wideband signal generating technique based on multiple-channel direct digital synthesis (DDS) in parallel is proposed for wideband radar signal generation. Using field programmable gate array chips, digital chirp signals are generated by the multiple-channel DDS architecture in each channel with variable phase difference at intermediate frequency. In addition, phase compensation is applied to multiple-channel signal before they are synthesized into a wideband signal at output by the high鄄speed digital/analog converter. Simulation and experimental results show that using the proposed technique, wideband signals can be generated at intermediate frequency in large instantaneous bandwidth at the advantages of easy implementation, high resolution in frequency and high-speed frequency conversion.

TN957. 5

国家自然科学基金资助项目(61571294);航空科学基金资助项目(20142057007,2015ZD07006)