Phase difference measurement circuit and measurement method based on field programmable gata array (FPGA) identical periodic signals

Abstract

The invention provides a phase difference measurement circuit and a measurement method based on field programmable gate array (FPGA) identical periodic signals and mainly solves the problems that phase difference of the periodic signals measured by the prior art is low in resolution ratio, and big in error. The phase difference measurement circuit and the measurement method based on the FPGA identical periodic signals comprise a first measurement channel, a second measurement channel and a logic control unit, wherein the first measurement channel and the second measurement channel are independent, the measurement progress of the first measurement channel and the second measurement channel is controlled by the logic control unit, and therefore delay of step-by-step taps of phase advance signals in the identical periodic signals is respectively finished the step-by-step taps of the number of delay taps are counted and the edges of two identical periodic signals are detected in an aligning mode, and phase difference of the identical periodic signals is counted according to counting results of the two channels. The phase difference measurement circuit and the measurement method based on the FPGA identical periodic signals are simple in structure and easy to realize, reduce measurement errors, improve measurement resolution ratios, and are capable of being used for measurement of phase difference of identical periodic signals of time synchronization, satellite navigation positioning and laser ranging.

Description

Technical field: [0001] The invention belongs to the technical field of time-frequency measurement and relates to a phase difference measurement, which can be used to measure the phase difference of the same period signal. Background technique: [0002] In the field of modern measurement, measuring the phase difference between two identical periodic signals is very important in engineering, especially picosecond-level measurement technology is particularly important, mainly used for time synchronization, satellite navigation positioning, laser ranging wait. In recent years, with the increasingly widespread application of digitalization, the measurement of signal frequency period is also developing towards digitalization. The advantages are high precision, strong adaptability and easy implementation. Realization of hardware chips such as digital processor DSP. [0003] The measurement methods of the same periodic signal mainly include the phase difference measurement based ...

AI Technical Summary

Problems solved by technology

The tap delay value determines the resolution of the measurement, but it is very difficult to construct a tap with a lower delay value and good linearity, and the tap delay value cannot be infinitely small

figure 1 is a schematic diagram of the existing tap delay method, figure 1 The true value of the measured phase difference of the same periodic signal is d, and the tap delay value is τ. During the measurement process, if the measured phase difference is an integer multiple of the tap delay value, after m-level delays, the true The value d is equal to the measured value mτ, and the measurement error ε is 0; however, if the measured phase difference is not an integer multiple of the tap delay value, after m delays, the measured value mτ will be greater than the true value d of the measured phase difference, As a result, the measurement error ε=mτ-d

Therefore, when using the tap delay method to measure any value of the phase difference of the same periodic signal, there will also be measurement errors

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