A new technique is proposed to measure the group velocity of sound by a frequency modulated (FM) continuous wave (CW) technique. Detailed calculations presented yield the results that Vx = (Awm/A<t>)d, where Vx, Aa>w, A<^» and d are, respectively, the group velocity, change of modulation frequency, phase change of the received signal detected by a biphase lock-in amplifier, and the distance travelled by the sound. The new approach has the advantage of high resolution compared to the conventional time-of-flight measurement technique.
|Original language||English (US)|
|Number of pages||4|
|Journal||IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control|
|State||Published - Sep 1989|
ASJC Scopus subject areas
- Acoustics and Ultrasonics
- Electrical and Electronic Engineering