随机振动中晶体振荡器的有源降噪设计

摘要

针对晶体振荡器在振动下会发生输出频率漂移的问题,在分析声学有源降噪技术和加速度对晶体振荡器输出相位噪声的影响机理基础上,提出降低随机振动中晶体振荡器噪声的方法.在晶体振荡器外围电路中嵌入加速度传感器、模数转换器、数模转换器和数字处理器,构建对晶体振荡器相位噪声进行实时补偿的有源降噪系统.结果表明:设计的有源降噪系统在0.03g/Hz振动幅度、10~850 Hz频率范围的随机振动条件下,能达到20 dB的相位噪声补偿效果.%Crystal oscillator output frequency often drifts under vibration.Therefore, based on the analysis of the acoustic active noise control technology and the mechanism of acceleration effect on crystal oscillator phase noise, a method of reducing crystal oscillator phase noise under vibration was proposed.The simulation about the acoustic active noise control system obtained that the theory of acoustic noise reduction can be used in crystal oscillator phase noise reduction.By adding acceleration sensor, analog-to-digital converter, digital-to-analog converter and digital processor in the peripheral circuit of crystal oscillator, the phase noise real time compensation active noise control system was constructed.The results show that the active noise control system achieves 20 dB phase noise compensation under the random vibration of 0.03g/Hz amplitude range and 10~850 Hz frequency range.