Implementation Of High-precision Frequency And Phase Digital Detection Technology Based On FPGA

With the development of information science and technology,there are higher requirements for the measurement of signal frequency,and obtaining high-precision measurement information is becoming crucial.In the 1960 s,high-precision digital frequency measurement technology began to appear.Compared with traditional analog evaluation,digital frequency measurement has the characteristics of good reliability,high accuracy,and high flexibility.Therefore,in the next few decades,digital frequency measurement has achieved rapid development,widely used in various fields.This article uses the digital-to-analog converter to complete the analog to digital conversion,and then completes the high-precision digital frequency measurement in the FPGA,completing the target task of the digital frequency measurement designed this time.In this paper,using the characteristics of suppression spectrum "leakage" and highprecision initial phase of all-phase FFT spectrum analysis based on traditional FFT spectrum analysis to complete two high-precision frequency measurement algorithms.The main contents of this article include :First of all,it investigated the development of high-precision digital frequency measurement technology and digital signal processing platform,and determined the basis of frequency measurement algorithm based on all-phase FFT spectrum analysis and FPGA-based data processing platform selected for this design.Then introduced several frequency measurement methods,which mainly introduced the detailed principle of FFT frequency measurement phase measurement method.Next,the spectrum analysis results of the all-phase FFT are introduced in detail and three frequency measurement algorithms are introduced on this basis.Then MATLAB simulation of these three algorithms is completed,and the measurement accuracy,advantages and disadvantages of the three algorithms are analyzed.Then the analog-digital convert board designed this time is introduced from the perspective of the function of the circuit,and the data acquisition test of the sampling board is completed.Then introduces the FPGA design part,which includes the FPGA implementation of the all-phase FFT phase difference method and the double spectrum lines method and the chip configuration module.It not only introduces the overall module implementation function,but also explains the specific principles of eachmodule.Board test,and the corresponding test results and analysis are given.It is analyzed that the phase difference of the all-phase FFT can achieve better than the result of reducing the fixed error by 80% when the signal-to-noise ratio is better,but it is more sensitive to noise and the all-phase FFT double spectral lines method has a certain antinoise performance because it uses a full-phase FFT amplitude spectrum similar to the power spectrum.At the end of the article,all the work and conclusions of this design are summarized,and the problems that need to be improved are also raised.Improving these problems has become the goal of future work.