Method and device for acquiring frequency offset by utilizing pre-fitting phase-locked frequency difference value

Abstract

The invention belongs to the technical field of detection, and discloses a method and device for obtaining frequency offset by utilizing a pre-fitting phase-locked frequency difference value. The method comprises the steps of segmenting a pre-fitting signal; carrying out frequency mixing calculation on the pre-fitting signal and two paths of phase-locked reference signals to obtain superposed signals of a difference frequency term and a sum frequency term, and carrying out low-pass filtering on the two paths of superposed signals; acquiring the amplitude ratio of the output signal to the phaselocking result of an original state signal of a probe to determine the position of a phase locking convergence point, and fitting a corresponding convergence site-frequency offset curve; dividing theacquired probe signal into N sections, and performing phase-locked filtering processing on each section and the pre-fitting signal to obtain a phase-locked convergence point position in the section;and obtaining the frequency offset corresponding to each convergence site according to the convergence site-frequency offset curve and the phase-locked convergence point position. According to the method, the micro-frequency offset of the AFM probe fluctuating on a high intrinsic frequency level in a strong noise environment can be accurately and quickly measured and calculated.

Description

technical field [0001] The invention belongs to the technical field of detection, and more specifically relates to a method and a device for obtaining a frequency offset by using a pre-fitted phase-locked frequency difference. Background technique [0002] Compared with the traditional DC steady-state field, which can only produce lower field strength, the strong magnetic field environment produced by the pulsed magnetic field provides greater possibilities for measuring the physical properties and magnetism of related materials. A large number of experiments have shown that: the external magnetic field reaches a certain When the intensity is high, the matter will be induced to appear various novel quantum phenomena. In actual measurement, behaviors such as magnetic moments, surface topological states, and SdH oscillations in the field of atomic physics are extremely microscopic, while the pulsed strong magnetic field device system provides an experimental environment with s...

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Problems solved by technology

[0008] In view of the defects of the prior art, the purpose of the present invention is to provide a method for obtaining the frequency offset by using the pre-fitted phase-locked frequency difference, aiming at solving the problem in the prior art of using the traditional The problem that the phase-locked loop detection method cannot obtain the oscillation frequency offset of the probe equipped with the AFM

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