For reducing the work noise, it is effective, to lower the work frequency.
为了减小工作噪音，降低工作频率是有效的。
2
Simulation results show the PLL clock frequency multiplier has lower phase noise and shorter capture time.
结果表明，PLL倍频器具有较低的噪声和较高的捕获速度。
3
The mechanism for low noise asphalt pavement to lower tyre noise is analyzed. A acoustical model is put forward. The resonance frequency of sound wave is analyzed with Helmholtz resonator model.