一种基于FPGA和SRD的超宽带混沌脉冲产生技术

An ultra-wideband chaotic pulse generation technology based on FPGA and SRD

在超宽带雷达系统中,混沌脉冲位置调制(CPPM)信号通常是由时间间隔按混沌变化的高斯脉冲序列组成,针对高斯脉冲的天线辐射效率低的问题,设计一种调制脉冲为单周期脉冲的超宽带CPPM信号源。首先数字仿真验证了Tent映射作为调制函数的可行性,然后利用FPGA模块和以阶跃恢复二极管(SRD)为核心的模拟电路模块获得了主脉冲宽度为590 ps、主峰峰值为-1.76 V且波形良好的单周期脉冲。自相关运算结果表明该信号具有良好的抗干扰能力和较高的检测概率;频谱图表明该信号没有直流成分,并且在低频区有极少的能量,作为雷达的发射信号时,可有效提高雷达天线的辐射效率。

In the ultra-wideband radar system,the chaotic pulse position modulation(CPPM)signal is usually composed of Gaussian pulse sequences with chaotic changes at time intervals.Aiming at the problem of low radiation efficiency of Gaussian pulses,and an ultra-wideband CPPM signal source of modulation pulse with single-cycle pulse is designed.Firstly,the digital simulation verifies the feasibility of Tent mapping as a modulation function.Then,he FPGA module and the analog circuit module with the step recovery diode(SRD)as the core,the main pulse width is 590 ps,the main peak value is-1.76 V and the waveform is obtained.The autocorrelation operation results show that the signal has good anti-interference ability and high detection probability;the spectrogram shows that the signal has no DC component and has very little energy in the low frequency region.When used as the radar signal,the radar can effectively improve the radiation efficiency of the antenna.