新型多频介电频散测井仪信号源设计

Design of multifrequency dielectric dispersion logging signal source

分析了新型多频介电频散测井仪的工作原理及应用,设计了一种新型多频介电频散测井仪的信号源方案。采用超奈奎斯特频率操作技术和SPI通信控制接口。硬件电路系统由基于DSP的通信控制板、基于多功能调制器AD9912的信号发生器板及声表面波滤波器组成。经过分析和实验验证,信号源的性能参数能满足测井的需要,为新型多频介电频散测井技术提供了新手段。

The application and the work principle of Multi frequency dielectric dispersion logging instrument are analyzed in this paper and a kind of new multi frequency dielectric dispersion logging signal source program is designed.The signal source is based on the super Nyquist frequency operation technology and SPI communication control interface protocol.The design scheme makes the circuit structure and control logic simple significantly.The hardware circuit consists of DSP communication control device,signal generator based on multi-function modulator(AD9912)and surface acoustic wave filter.The frequency control word of signal generator panel sets through the SPI interface protocol,the frequency of output signal adjusts by the circuit.At the same time,the output frequency agility,high spectrum purity,broadband (20MHz-1GHz)microwave signal generate by using ultra Nyquist frequency technique based on SAW(surface acoustic wave)filter.The experiments and test results are in good accordance with the requirements and performance of multi frequency dielectric dispersion logging.