Analysis of the performance of underwater acoustic parametric array under different input signals

According to Berktay the far-field solution of parametric array, self-demodulatory sound pressure is proportional to squared of envelope function to the second derivative of the time. The excitation input signals of parametric array were designed and analyzed. A parameter array is measured under the different excitation signals. The results show that: (1) When the input signals is single-sideband amplitude modulatory signal the harmonic distortion of the sound field is relatively small compared to the double sideband amplitude modulated signal and the difference frequency wave acoustic source level is higher; (2) The difference frequency wave source level will increase rapidly with increase of input power of the parametric array. But too much power may cause the power amplifier to produce nonlinear, thus the harmonic amplitude increase and the conversion efficiency will be lower.