Determination of Phase Jumps in the Measurement of Phase Velocity of Samples Obeying a Frequency Power-Law Attenuation Coefficient Using Krames-Krong Relations

Autor(es)

Elvira, Luis ^[1] ; Tiago, Marcelo Moreira ^[2] ; Yoza, Suelen A. N. ^[3] ; Kitano, Claudio ^[3] ; Higuti, Ricardo Tokio ^[3]

Afiliação do(s) autor(es)

^[1] CSIC, Inst Tecnol Fis & Informac, Madrid 28006 - Spain

^[2] Fed Univ Ouro Preto UFOP, Inst Exact & Appl Sci ICEA, Dept Elect Engn, BR-35931008 Joao Monlevade - Brazil

^[3] Sao Paulo State Univ UNESP, Sch Engn Ilha Solteira, BR-15385000 Ilha Solteira - Brazil

• Tipo de documento: Artigo Científico
• Fonte: IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL; v. 67, n. 7, p. 1438-1447, JUL 2020.
• Citações Web of Science: 0

Resumo

Ultrasonic phase velocity spectroscopy is a very sensitive technique used in the measurement of material properties. In a phase velocity calculation, ambiguities can arise in the spectral phases, in the form of integer multiples of 2 pi rad, which, if not corrected, results in large errors. In this work, we propose a method for determining these ambiguities, more specifically, the number of 2 pi rad phase jumps, using the Kramers-Kronig relations, for samples exhibiting a frequency power-law attenuation coefficient. The method is based on a first estimate of the phase velocity from group velocity and attenuation coefficient that are not affected by phase jumps. This estimated phase velocity is used to obtain the number of 2 pi rad phase jumps, which in turn is used to calculate the corrected phase velocity. The method was tested with samples of liquids with a frequency power-law attenuation coefficient (exponent y varying from 1.5 to 2) and a solid {[}polymethyl methacrylate (PMMA)] with y similar to 1, and velocity dispersions ranging from 0 to 34 (cm/s)/MHz. (AU)

• Processo FAPESP: 14/09034-8 - Medição de propriedades de líquidos por ultrassom com altas frequências
• Beneficiário: Ricardo Tokio Higuti
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/09038-3 - Métodos para caracterização de líquidos por ultrassom
• Beneficiário: Ricardo Tokio Higuti
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional