A high-precision frequency measurement system and method based on sampling frequency conversion technology

Abstract

The invention discloses a high-precision frequency measurement system and method based on sampling frequency conversion technology, including: an intermediate frequency processing part, a radio frequency calculation part and a radio frequency verification part connected in sequence; - Input the local oscillator to measure the intermediate frequency, judge whether the intermediate frequency measurement result meets the frequency measurement resolution requirement, and judge whether there is an intermodulation signal affecting the measurement in the intermediate frequency measurement result, and if it exists, perform intermodulation elimination; the radio frequency calculation part is used to process the part according to the intermediate frequency The intermediate frequency values ​​measured twice are used to calculate the harmonic order, sign and corresponding radio frequency value; the radio frequency verification part is used to verify whether the radio frequency value calculated by the radio frequency calculation part is a harmonic signal, if it is a harmonic signal then Perform harmonic elimination. The invention has beneficial effects: stable measurement of high-frequency signals can be realized; intermodulation signals affecting the measurement can be effectively eliminated to perform correct frequency measurement; harmonics can be identified and effectively eliminated.

Description

technical field [0001] The invention relates to a high-precision frequency measurement system and method based on sampling frequency conversion technology. Background technique [0002] When the sampling frequency conversion technology is used for frequency measurement, it is necessary to mix the local oscillator and its harmonic signals with the measured signal to generate an intermediate frequency signal. The intermediate frequency signal falls in the intermediate frequency band again, and the intermediate frequency before and after fine-tuning is measured respectively. According to the intermediate frequency before and after fine-tuning, the frequency value of the signal under test can be obtained. At the same time, the intermediate frequency signal and its harmonics will overlap and mix with the local oscillator and its harmonics again, so that many intermodulation signals of different frequencies are mixed at the output end of the mixer. When the frequency of the inter...

AI Technical Summary

Problems solved by technology

Through a series of methods such as intermediate frequency stability detection, intermodulation elimination and radio frequency calibration, the following problems in the process of converting high frequency signals into lower frequency intermediate frequency signals through samplers are solved:

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