Correction of Low Frequency Component in Spectrum Analysis Based on Hilbert Transform

Abstract:

Because of the serious interference coming from the negative frequency in low frequency correction, the traditional correction methods no longer work. This paper proposes an improved ratio method to correct the frequency, phase and amplitude of spectrum peak when the spectral line locates near the left end in spectrum. The Hilbert Transform is used to diminish the impact of interference of the mirror frequency. The barycenter of two spectral lines is used to obtain the correcting value. A new formula is developed when the frequency is less than the frequency resolution. One of the spectral lines is located in the main lobe and the other is in the first side lobe. Furthermore, the direct current has nearly no impact on this new method theoretically which is a key problem in low frequency correction. The simulation shows that the frequency, phase and amplitude of a theoretical low frequency can be corrected satisfactorily. The result of the correction improves a lot compared with the traditional method. However, this method could not correct the spectrum with multiple components of low frequency.

• Periodical: Key Engineering Materials (Volume 584)
• Pages: 154-158
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.584.154
• Online since: September 2013
• Authors: Jun Jie Wang, Zhi Jiang Xie, Ping Chen
• Keywords: Analytic Signal, Frequency Correction, Hilbert Transform, Ratio Method

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