双路相参脉间随机捷变频频综的设计与仿真

Design and simulation of dual coherent random agile among pulse frequency synthesizer

提出了一种双路相参脉间随机捷变频频综器的设计方法,设计采用双路DDS产生具有一定带宽的脉间频率捷变信号与S波段跳频源上变频,使频综器在DDS频带内实现脉间随机捷变,在PLL频带内实现脉冲串间跳变。通过对设计难点的说明,重点分析了DDS的杂散情况,选择出满足设计的DDS芯片及频段;同时设计需要产生两路相差30MHz相参中频的DDS信号,以便于接收电路在中频进行相参处理。通过对相参脉冲频谱特性进行分析,确定仿真方案,最终仿真证明两路DDS相差的信号具有良好的中频相参特性。

A design methodology for dual coherent random agile among pulse frequency synthesizer is introduced in this paper.A dual DDS is used in this design to attain a certain bandwidth of the signal pulse agile up-conversion with S-band frequency hopping source,by which the synthesizer achieves random agile and skipping respectively among pulse frequency in DDS-band and burst pulse in PLL-band.Based on the description of the design difficulties,by studying DDS scattering,the DDS chip and its frequency range is selected to meet the design requirements,while this design needs a 30 MHz coherent IF between two DDS so that processing of coherent can be completed in the IF of receiver circuit.A simulation program is determined based on analysis of coherent pulse spectrum.The results from simulation show that the difference signal from the two DDS is characterized by good coherent performance.