核磁共振测井仪发射滤波模块设计与应用

Design and Application of Transmitter Filter Module in Multi-frequency NMR Logging Tool

基于核磁共振测井仪高压发射滤波原理,设计出一种串并联谐振组合的滤波电路,滤除核磁共振测井仪高压射频脉冲谐波信号。推导了滤波模块中串联谐振模型和并联谐振模型,得出滤波模块谐振频率参数。先设计滤波模块谐振频率,再实际调试谐振频率并进行对比分析,实际调试得到的谐振频率能显著提高高压发射脉冲有效功率,有利于减小仪器高压电源负荷,提高仪器整体性能。

based on the high voltage transmitting works of NMR logging tool,designed is a combination of series and parallel resonant filter circuit to filter out the high-voltage harmonic RF pulse of the NMR logging tool.The series and parallel resonant model of transmitter filter module are derived,and the resonance frequency parameters of filter module are obtained.Compared with design resonant frequency and the actual debugging resonant frequency,the later frequency can significantly improve the useful power of high-voltage transmit pulse,which will reduce the load of high voltage power supply equipment and improve the overall performance of the instrument.