Frequency and phase difference precision measurement method based on frequency and phase relationship auxiliary processing

Abstract

The invention discloses a frequency and phase difference precision measurement method based on frequency and phase relationship auxiliary processing. The frequency and phase difference precision measurement method comprises the following steps of: allowing a 10-MHz frequency scale output by a caesium clock to pass through a shaping circuit and an adjustable pulse generation circuit to generate a pulse signal; automatically synthesizing frequency f0 by using a digital display scope (DDS), wherein the value of the f0 depends on fx roughly measured by a singlechip microcomputer, so that the integer multiple of the group period of the fx and the f0 is equal to the time value of a gate and the value of the group phase quantum of the fx and the f0 is equal to the resolution ratio of a group phase coincidence detection circuit; transmitting the f0 and the fx to a pilot frequency phase coincidence detection circuit to generate the actual measurement gate; controlling work of a counter; calculating the value of the fx according to the counting result by using a microprogrammed control unit (MCU); and finally displaying output by using a liquid crystal display (LCD). According to the frequency and phase difference precision measurement method disclosed by the invention, one DDS is introduced to determine the frequency relationship between the fx and the f0, and a good measuring effect of any frequency signals within the required gate time is achieved.

Description

technical field [0001] The invention relates to a frequency and phase difference precision measurement method based on auxiliary processing of frequency and phase relationship. Background technique [0002] There are many methods for frequency measurement, and the accuracy of frequency measurement mainly depends on the frequency range to be measured and the characteristics of the measured object. The accuracy that can be achieved in measurement depends not only on the accuracy of the frequency source used as a standard, but also on the measurement equipment and measurement methods used. The commonly used frequency measurement methods are: [0003] (1) Direct frequency measurement method [0004] The direct frequency measurement method is the pulse filling method, which is the simplest frequency measurement method. Its main measurement principle is to fill in pulses in a given gate signal, and get the number of filled pulses through the necessary counting circuit, so as to...

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Problems solved by technology

However, since the frequency value of the measured signal is uncertain, the law of its phase relationship with the frequency standard signal is also uncertain, so the frequency measurement scheme based on the group phase relationship can only achieve high resolution for certain frequency points. high-resolution measurement of arbitrary frequency signals

[0020] The ultra-high-resolution frequency measurement scheme based on the group phase relationship has been found to have two problems during its continuous use: 1. When the frequency value of the measured signal is too close to the frequency value of the frequency standard signal, due to the large group period , the actual gate cannot be formed, and the measurement cannot be performed; 2. When the frequency relationship between the measured signal and the frequency standard signal is complicated, the value of the phase quantum is too small, and the distribution of the group phase coincidence points is complicated, and the accuracy of the group phase detection decreases , so that the final frequency measurement resolution is reduced by

In fact, in the actual frequency measurement process, since the frequency value of the measured signal is uncertain, it is difficult to determine the frequency relationship between it and the frequency standard signal, so there is great uncertainty in the change law of the phase relationship between them Therefore, frequency measurement schemes based on group phase relationship processing can only achieve high-resolution measurement of signals at certain frequency points, but cannot achieve high-resolution measurement of arbitrary frequency signals

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