交叉偶极阵列声波测井仪模拟通道电路设计

Design of Analog Channel Circuit for Cross-dipole Acoustic Array Logging Tool

针对交叉偶极阵列声波测井仪高温、强背景噪声的作业环境,采用模拟滤波、低噪声设计和优化的布局布线等技术设计交叉偶极前置模拟通道电路,以实现声波信号接收、波形模式选择、程控增益放大、有源带通滤波等功能。该文详细地阐述了如何抑制高频噪声干扰以及降低电路自身的噪声影响,着重分析和介绍了低噪声前置预放大电路和有源带通滤波器的设计。实验结果表明,该模拟电路噪声小,有较强的噪声抑制能力,通道间波形一致性较好,能在井下恶劣环境中稳定可靠地工作。

In order to make Cross-dipole Acoustic Array Logging Tool fit for operating in noisy environment and at high temperature,signal conditional circuit,which was primarily applied to select wave modes,control the signal gain by programs and attenuate noises through band-pass filters,were designed with some technical skills,such as analog filtering,low noise electronic design and optimal layout.This paper puts emphasis on analyzing and designing the amplifier circuits located forward and the band-pass filters,aiming at suppressing interference from high frequency noises and decreasing noises generated itself.Experiments show that this conditional circuit with low noise,strong ability of suppressing noises and good consistency between signals from different channels,can operate stably and reliably at high temperature.