An FPGA-based frequency response analyzer for multisine and stepped sine measurements on stationary and time-varying impedance
An FPGA-based frequency response analyzer for multisine and stepped sine measurements on stationary and time-varying impedance
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DOI：
10.1088/0957-0233/25/1/015501
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发表时间：
2014-01-01
影响因子：
2.4
通讯作者：
Bragos, R.
中科院分区：
文献类型：
--
作者：
Sanchez, B.;Fernandez, X.;Bragos, R.
报道了一种基于现场可编程门阵列(现场可编程门阵列)的频响分析仪(FRA)的研制，用于利用周期性激励(即正弦波和多正弦波)测量阻抗频率响应函数(FRF)。步进式正弦测量使用两个专用的硬件构建的数字嵌入式乘法器模块来提取输出信号的相位和正交分量。多正弦FRF测量计算输入/输出信号的快速傅立叶变换(FFT)。在本文中，我们描述了它的设计、实现和性能评估，并对模体进行了阻抗谱(EIS)测试。在1k Omega(1%)下，阶跃正弦精度为1.21%，精度为35m Omega，总的谐波失真加噪声(THD+N)为-120分贝。对于多正弦阻抗频响函数的测量，当测量505Omega(1%)电阻时，其幅值和相位精度在48.828 kHz时为0.23Omega，在8.087 MHz时为0.021°。在8.087 MHz频率下，幅值精度为0.55%，在6.54 MHz频率下，相位精度为0.17°。在频率为1 MHz以下和高于1 MHz时，阶跃正弦信噪比分别为84和65分贝。多正弦频响测量的信噪比大于65分贝(30 kHz-10 MHz)。频率范围为610.4兆赫-12.5兆赫，以30千赫频率开始的多正弦激励的最大频率为200谱S(-1)。基于其技术规格和通用性，提出的FRA可用于许多应用，例如，快速了解被测时变阻抗的瞬时阻抗FRF。
We report the development of a field programmable gate array (FPGA) based frequency response analyzer (FRA) for impedance frequency response function (FRF) measurements using periodic excitations, i.e. sine waves and multisines. The stepped sine measurement uses two dedicated hardware-built digital embedded multiplier blocks to extract the phase and quadrature components of the output signal. The multisine FRF measurements compute the fast Fourier transform (FFT) of the input/output signals. In this paper, we describe its design, implementation and performance evaluation, performing electrical impedance spectroscopy (EIS) measurements on phantoms. The stepped sine accuracy is 1.21% at 1 k Omega (1%), the precision is 35 m Omega and the total harmonic distortion plus noise (THD+N) is -120 dB. As for the multisine impedance FRF measurements, the magnitude and phase precision are, respectively, 0.23 Omega at 48.828 kHz and 0.021 deg at 8.087 MHz when measuring a resistor 505 Omega (1%). The magnitude accuracy is 0.55% at 8.087 MHz while the phase accuracy is 0.17 deg at 6.54 MHz. In all, the stepped sine signal-to-noise ratio (SNR) is 84 dB and 65 dB at frequencies below and above 1 MHz respectively. The SNR for the multisine FRF measurements is above 65 dB (30 kHz-10 MHz). The FRA bandwidth is 610.4 mHz-12.5 MHz and the maximum FRF measurement rate exciting with multisines starting at 30 kHz is 200 spectra s(-1). Based on its technical specifications and versatility, the FRA presented can be used in many applications, e.g. for getting insight quickly into the instantaneous impedance FRF of the time-varying impedance under test.