Quasi full-synchronous high-precision rapid frequency measuring device and method

Abstract

The measuring device includes waveform shaping circuit, crystal oscillator, programmable device, CPU and display unit. The input end of the waveform shaping circuit is connected to the input end of the programmable device. Connecting the programmable device, the crystal oscillator provides clock source for the programmable device. The programmable device is connected to CPU. CPU is in use for calculating frequency value. The output end of CPU is connected to the input end of the display circuit. The display circuit displays calculated result. Measuring phase difference between signal to be measured and standard clock raises measuring accuracy. Advantages are: quick measuring frequency with high precision, simple structure of circuit hardware, using dedicated chip to measure frequency to reduce cost, and using FPGA to implement the device.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a quasi-full synchronous high-precision fast frequency measurement device and a measurement method. Background technique [0002] The existing commonly used frequency measurement methods are M method, T method and M / T method. The M method calculates the frequency of the signal to be tested by measuring the pulse number of the signal to be tested within the standard gate time, and its accuracy depends on the gate width and the frequency of the signal to be tested. The T method obtains its frequency by measuring the period of the signal to be measured and calculating its reciprocal, and its measurement accuracy depends on the period and timing accuracy of the signal to be measured. Therefore, the measurement accuracy of T method and M method is low. The M / T method uses the period measurement method for low-frequency signals and the frequency measurement method for high-fre...

AI Technical Summary

Problems solved by technology

The main disadvantage of the M / T method is that due to the existence of ±1 error, it is difficult to measure both low-frequency and high-frequency accuracy, so the measurement accuracy is low

But the hardware circuit is difficult to realize

[0013] The currently used frequency measurement method has the disadvantages of low precision and a counting error of ±1; the measurement speed is relatively slow, the circuit structure is complex and difficult to implement, etc.

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