宽带参量阵的研究(2)原波信号包迹的影响

本文提出两种接近实际的原波信号包迹,进一步研究了其脉冲自解调现象中的宽带参量信号的波形及频谱特征。结果表明,第一类包迹信号的参量声频谱的主要成分偏向高频域。而对第二类包迹信号来说,除了有第一类包迹信号的参量声压频谱成分以外,还包含低频成分。如果原波信号是脉冲列,则参量声压频谱随脉冲占空比作周期性变化。

TRANSIENT PARAMETRIC ARRAYS (2) TWO KINDS OF PRIMARY ENVELOPES

In the paper two kinds of primary envelopes which are close to actual conditions are suggested,and the transient parametric pressure waveforms as well as thier spectra resulting from the self-demodulation of pulses are investigated.It is shown that the spectral components referred to the first kind of primary envelopes are in the higher frequency domain.However,for the second kind of primary envelopes,besides the above-mentioned spectral components more abundent components in lower frequency domain are contained.When a pulse train is available,the spectrum of parametric pressure has a periodic variability with its pulse duration ratio.