关键词: 耦合Duffing振子, 微弱脉冲信号, 实时检测, 现场可编程门阵列

Abstract: In order to detect weak electromagnetic pulse signals in wideband noise at a real-time rate, the detection algorithm and FPGA implementation were researched. According to the phenomenon of general "in-well out-of-synchronization" in the strongly coupled Duffing oscillators caused by the pulse signal, the original weak pulse signal could be detected through the principle of variable difference. The Duffing differential equations were solved by a real-time algorithm named fourth-order Runge-Kutta, which has the advantage of maximum stability domain and minimum truncation error. We devised a pulse detection pipeline structure that was suitable for running on the FPGA. In order to improve the detection rate,a data parallel structure was designed to calculate 73 segments of data simultaneously. To avoid the problem of waveform distortion caused by parallel computing, we separated the threshold detection process from the waveform extraction process by adding a FIFO memory. Experimental results show that the minimum detectable signal-to-noise ratio can reach-18dB in the detection of weak lightning electromagnetic pulses.

Key words: coupled Duffing oscillators, weak pulse signal, real-time detection, FPGA(Field Programmable Gate Array)