基于ARM9+FPGA频谱仪的设计与实现

The design and realization of spectrometer based on ARM9+FPGA

为实现低频段信号频谱的测量与显示，设计一款以ARM9与FPGA为核心，采用FFT算法求取信号频谱的便携式频谱仪．ARM9是系统的控制单元，运行Linux操作系统，采用Qt／GUI管理操作界面．FPGA是数字信号处理单元，控制A／D采样与运行FFT算法；并采用速率为105MHz的高速A／D芯片，7英寸彩色LCD触摸屏，以及增益高达60dB的放大电路等模块．经研制并测试，该频谱仪的频谱测量范围为0～50MHz，分辨率最小为1Hz，具有测量精度高、成本低和携带方便等优点，利于推广应用．

In order to realize the measurement and display of low frequency band signal, this paper introduces a portable spectrometer based on the ARM9 and FPGA, which uses FFT algorithm to transform signal spectrum. As the control unit of system, the ARM9 runs Linux operating system and adopts Qt/GUI as operation interface. The FPGA, as digital signal processing unit, controls A/D sampling and runs FFT algorithm. A high speed A/D chip with sampling rate of 105 Msps, a 7-inch colorful LCD touch screen, and amplification circuit of gain up to 60 d B are applied to this design. The test result of the spectrometer shows that the spectrum measurement range is 0-50 MHz and the minimum resolution is 1Hz. The spectrometer has the advantages of high precision, low cost and easy portability, which is good to popularize and apply.