传声器失配误差对差分传声器圆阵主瓣指向的影响特性

从理论上导出了传声器失配误差对适用于任意阵元数的一阶和二阶差分传声器圆阵的主瓣指向影响规律。揭示了传声器相位误差可造成一阶差分传声器圆阵主瓣指向产生反转现象,是影响其主瓣指向的主要因素。而对于二阶差分传声器圆阵,传声器相位误差和增益误差均可导致其主瓣指向产生反转现象和严重指向误差,进而造成阵列指向性因子严重下降,尤其在低频处失配误差的影响更为显著。然后给出了确保差分传声器圆阵主瓣指向正确时阵列设计参数所需满足的条件,并在此基础上进行了传声器失配误差的容差分析。分析结果表明,随着阵元数增多,失配误差的容差范围增大,差分传声器圆阵对传声器失配误差的敏感性相应降低。 

On mainlobe orientation of circular differential microphone array in the presence of sensor imperfections

The impact of sensor imperfections on the mainlobe orientation of the first-and second-order Circular Differential Microphone Array（CDMA） applicable to arbitrary number of array elements is theoretically investigated.It is revealed that the microphone phase mismatches can cause the mainlobe orientation reversal phenomenon of the first-order circular CDMA,which is the main factor affecting the mainlobe orientation.For the second-order CDMA,the microphone phase and gain mismatches can lead to the mainlobe orientation reversal and serious orientation deviation,which leads to the serious deterioration of the array directivity factor,and especially the effect is more remarkable in lower frequencies.Then,the conditions on the design parameters of the first-and second-order CDMA are derived to ensure correct mainlobe orientation,and on this basis,the microphone imperfections tolerance analysis is performed.The analysis results show that with the increase of the number of array elements,the tolerance increases,and the sensitivity of the CDMA to microphone imperfections is decreased accordingly.