基于FPGA与Qsys的宽带高精度频率计的设计与实现

Design and implementation of wide-band and high-precision frequency meter based on FPGA and Qsys

频率是电子信息领域中重要的物理量之一,为了实现对信号频率的宽频带、高精度测量,采用"三计数器同步并行计数法"设计了一种基于FPGA与Qsys的测量系统.首先通过信号调理电路对输入的信号进行整形处理,然后输入至FPGA进行脉冲计数,最后使用Qsys在FPGA上构建Nios II处理器对信号进行处理与运算,并在液晶屏上显示测量结果,实现了频率的宽频带、高精度测量,并增加了周期测量、正占空比测量和时间间隔测量等测量功能.经测试,系统可实现1Hz～300MHz正弦信号的频率测量,测量误差不大于0.002%.结果表明,与传统的频率测量方法相比,数据处理部分采用一片FPGA即可实现,系统测量精度高、测量迅速、稳定性高,可以应用在仪器仪表中.

Frequency is one of the important physical quantities in the field of electronic infor mation,in order to measure the frequency in high precision and wide band,a measurement system based on FPGA and Qsys is designed using ＂ three counters synchronous parallel counting method＂. First,the input signal is shaped by the signal conditioning circuit,and then input to FPGA for pulse counting,finally,the Nios II processor is built in FPGA using Qsys to process and calculate the signal, and the measurement results are displayed on the LCD screen, wide band, high precision measurement of frequency is achieved, and measurement functions such as period measurement, positive duty cycle measurement, and time interval measurement are added. After testing,the system can achieve 1 Hz^300 MHz sinusoidal sig nal frequency measurement, the measurement error is not greater than 0. 002%. The result shows that compared with the traditional frequency measurement method, the data processing part can be realized with a single FPGA, the system has high measurement accuracy, short measurement period and high stability,and can be applied in the instruments.