基于STM32和FPGA的远程宽带幅频特性测试系统

A long-range wide-band amplitude-frequency characteristics test system based on STM32 and FPGA

介绍一种基于STM32与FPGA双控制核心的远程宽带大动态范围的幅频特性测试装置。该装置采用直接数字频率合成芯片AD9959产生频率和幅度均可控的正弦信号,并将其发送至待测网络。接收端对待测网络的输出信号进行可变增益放大和欠采样数字峰值检测后,将幅频信息通过WiFi模块无线传输至上位机进行幅频特性曲线的显示。该装置具有500 kHz～100 MHz的宽带扫频范围,52 dB的大动态范围,灵敏度可达100μV,支持多节点测试。由于采用了欠采样技术,该系统不需要高速ADC即可完成宽带信号采样,具有成本低、易维护等特点,可满足分布式测量、野外作业等特殊场景下的幅频特性测试需要,具有广阔的应用前景。

A long-range amplitude-frequency characteristics test device based on STM32 and FPGA is introduced in this paper. The device generates a sinusoidal signal with controllable frequency and amplitude by means of direct digital frequency synthesis chip AD9959,and then sends the signal to the network under test. The variable gain amplification and undersampling digital peak detection are carried out for the output signal of the network under test in the receiving end,and then the amplitude. frequency messages are sent to the host computer through the WiFi module for display of amplitude.frequency characteristics curve. The device has the wide-band sweep frequency range of 500 kHz^100 MHz,amplitude dynamic range of 52 dB,voltage sensitivity highest to 100 μV,and supports multi-node test. The proposed system using undersampling technology can complete the wide-band signal sampling without high-speed ADC,has the characteristics of low cost and easy maintenance,can meet the demand of amplitude-frequency characteristics testing in some unique scenes such as distributed measurement or field operation, and has broad application prospect.