取样示波器等效采样系统设计与实现
发布时间：2018-07-22 10:33
【摘要】：随着电子科学技术的迅猛发展,电子信号传输的复杂性和多样性的特征愈加明显,对这些信号的测量的要求也越来越高。取样示波器作为一种测量高速信号的仪器,利用其独特的采样结构,采用等效采样的原理,能够达到普通实时示波器的十倍以上采样率和系统带宽。本论文所设计的取样示波器等效采样系统依托同样采用等效采样原理进行采样的特性阻抗分析仪平台。由于现有平台无法进行多通道测量,因此重新设计了多通道采集电路和差分处理电路。由于现有电路没有对信号进行滤波,因此有必要增加滤波电路。为了增加偏置处理和增益处理这两项功能,设计了DAC来实现可由FPGA控制的偏置电路和增益电路。重新设计了系统的时钟电路,提供了更稳定的时钟信号。在此基础上,通过编写FPGA控制程序来实现基于“粗延时+细延时”的等效采样功能、平均测量功能、多通道测量功能、差分测量功能、可调偏置功能以及可变增益功能。最终取样示波器等效采样系统实现了顺序等效采样。采用100GSPS的等效采样率对100MHz正弦波采样,SNR达到了64.68d B,实现了对高速信号的采样。双通道测试时数据一致性得到改善,新加的平均测量功能、多通道测量功能、差分测量功能、可调偏置功能以及可变增益功能也得到实现。测试中,AD9251对100KHz,400m Vp-p正弦波信号进行采集,信噪比SNR达到了70.16d B,总谐波失真THD为-74d B,成功实现了数据采集。当前所设计的等效采样系统的硬件平台和程序已经在最新的特性阻抗测试中得到应用。
[Abstract]:With the rapid development of electronic science and technology, the complexity and diversity of electronic signal transmission become more and more obvious. Sampling oscilloscope is a kind of instrument for measuring high speed signal. By using its unique sampling structure and the principle of equivalent sampling, the sampling rate and system bandwidth of ordinary real time oscilloscope can be achieved by more than ten times. The sampling oscilloscope equivalent sampling system designed in this paper is based on the characteristic impedance analyzer which also adopts the principle of equivalent sampling. The multi-channel acquisition circuit and differential processing circuit are redesigned because the existing platform can not carry out multi-channel measurement. Since the existing circuits do not filter the signal, it is necessary to increase the filter circuit. In order to increase the functions of bias processing and gain processing, a DAC is designed to realize the bias circuit and gain circuit which can be controlled by FPGA. The clock circuit of the system is redesigned to provide a more stable clock signal. On this basis, the FPGA control program is written to realize the equivalent sampling function, the average measurement function, the multi-channel measurement function, the differential measurement function, the adjustable offset function and the variable gain function based on "coarse delay and fine delay". The final sampling oscilloscope equivalent sampling system realizes sequential equivalent sampling. The SNR of 100 MHz sinusoidal wave sampling can reach 64.68 dB with the equivalent sampling rate of 100GSPS, and the high speed signal can be sampled. The data consistency is improved during the two-channel testing. The new average measurement function, the multi-channel measurement function, the differential measurement function, the adjustable bias function and the variable gain function are also realized. The signal to noise ratio (SNR) is 70.16 dB, the total harmonic distortion THD is -74 dB, and the data acquisition is successful. The hardware platform and program of the current equivalent sampling system have been applied in the latest characteristic impedance test.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM935.38
本文编号：2137147
[Abstract]:With the rapid development of electronic science and technology, the complexity and diversity of electronic signal transmission become more and more obvious. Sampling oscilloscope is a kind of instrument for measuring high speed signal. By using its unique sampling structure and the principle of equivalent sampling, the sampling rate and system bandwidth of ordinary real time oscilloscope can be achieved by more than ten times. The sampling oscilloscope equivalent sampling system designed in this paper is based on the characteristic impedance analyzer which also adopts the principle of equivalent sampling. The multi-channel acquisition circuit and differential processing circuit are redesigned because the existing platform can not carry out multi-channel measurement. Since the existing circuits do not filter the signal, it is necessary to increase the filter circuit. In order to increase the functions of bias processing and gain processing, a DAC is designed to realize the bias circuit and gain circuit which can be controlled by FPGA. The clock circuit of the system is redesigned to provide a more stable clock signal. On this basis, the FPGA control program is written to realize the equivalent sampling function, the average measurement function, the multi-channel measurement function, the differential measurement function, the adjustable offset function and the variable gain function based on "coarse delay and fine delay". The final sampling oscilloscope equivalent sampling system realizes sequential equivalent sampling. The SNR of 100 MHz sinusoidal wave sampling can reach 64.68 dB with the equivalent sampling rate of 100GSPS, and the high speed signal can be sampled. The data consistency is improved during the two-channel testing. The new average measurement function, the multi-channel measurement function, the differential measurement function, the adjustable bias function and the variable gain function are also realized. The signal to noise ratio (SNR) is 70.16 dB, the total harmonic distortion THD is -74 dB, and the data acquisition is successful. The hardware platform and program of the current equivalent sampling system have been applied in the latest characteristic impedance test.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM935.38
【参考文献】
相关硕士学位论文 前1条
1 王丹;基于等效采样的高速数据采集系统的设计与实现[D];长春工业大学;2010年
，本文编号：2137147
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