一种多频率同步信号激励电流源设计  

Design of a multi-frequency synchronized signal excitation current source

作　　者：杨宇祥[1] 乔洋[1] 

机构地区：[1]西安理工大学机械与精密仪器工程学院,西安710048

出　　处：《仪器仪表学报》2013年第4期908-913,共6页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(61273271;30900317);中国博士后科学基金(20110491674);教育部博士点新教师基金(20096118120006)资助项目

摘　　要：生物电阻抗频谱(BIS)多频率同步快速测量系统中的激励电流源必须满足频谱宽、谱能量均衡、相位同步、输出阻抗高等特殊要求。基于Walsh函数设计了一种周期、二值的九频率同步信号f(9,t),它在1、2、4、8、16、32、64、128和256次等9个主谐波上相位同步,能量分布均衡,功率总和占到了平均总功率的65.52%。介绍了f(9,t)的FPGA实现方法和电压控制电流源(VCCS)驱动电路设计。负载实验表明,VCCS的负载电压理论仿真波形与实测波形高度一致,且具有较高的输出阻抗。确立了一种比较理想的多频率同步激励电流源,为BIS的多频率同步快速测量奠定基础。The excitation current source in bioimpedance spectroscopy （BIS） multi-frequency synchronized fast meas- urement system must meet the special requirements of wide frequency spectrum range, homogeneously distributed spectrum energy, synchronous phase and high output impedance. This paper designs a periodical and two-valued nine- frequency synchronized signal f（9,t） based on Walsh functions.f（9,t） includes nine primary harmonics at 1st ,2ha, 4th, 8th, 16th, 32na, 64th, 128tg and 256th harmonics, which have synchronous phase, homogeneously distributed spec- trum energy and 65.52% of the total average power of the signal. The field programmable gate array （FPGA） imple- mentation method off（9, t） and the driving circuit design of the voltage-controlled current source （VCCS） are intro- duced. Load experiments were performed and the results show that the theoretical simulation voltage waveform and the real experiment voltage waveform on the VCCS load are highly consistent, and the VCCS has fairly high output imped- ance. This paper establishes an ideal multi-frequency synchronized signal excitation current source and lays a founda- tion for the multi-frequency synchronous fast measurement of BIS.

关 键 词：生物电阻抗频谱 多频率同步信号 FPGA 电压控制电流源 

分 类 号：TM938.84[电气工程—电力电子与电力传动] R318.03[医药卫生—生物医学工程]