基于FPGA的电阻抗成像系统激励信号源

FPGA Based Signal Generator in EIT System

针对人体电阻抗成像系统的要求，设计并实现了一种基于FPGA的激励信号源，输出频率范围为0～1．5MHz．通过对正弦波进行泰勒级数插值，使信号源的精度得到改进；其频率、相角及幅值可调；不需改动外部电路，即可工作在单频、多频和扫频模式下．实验结果表明，该信号源精度高，幅值稳定性好，调节方便，可满足不同激励模式下人体电阻抗成像系统的需要．

A FPGA based signal generator is designed and implemented. The frequency covers from 0 to 1.5 MHa The precision of the signal generator is improved significantly with Taylor series corrected method. The frequency, phase and amplitude of the signal source can be controlled. Moreover, single frequency, multi-frequency and sweep frequency signals can also be generated without modifying external hardware_. Experimental results show that this signal generator is of high precision and stability, and is an ideal module for electrical impedance tomography system of different exciting modes.