| 摘要 |
PROBLEM TO BE SOLVED: To improve an SN ratio by the erasure of a backward transmission wave or an increase in the amplitude of a forward transmission wave even when a phase velocity and a group velocity are different.SOLUTION: A wave transmission method according to an embodiment includes a transmission step in which each of a first sensor 11 and a second sensor 12 transmits a wave packet in which a phase velocity and a group velocity are different. Assuming a phase velocity Vph, a group velocity Vg, a first integer n that is an integer greater than or equal to 1, and a wavelength λ of a transmitted wave, and that a distance L between the first sensor 11 and the second sensor 12 satisfies equation (1) below, one of the first sensor 11 and the second sensor 12 starts transmitting a wave in the transmission step with a timing and a phase difference that cancel or amplify the wave transmitted by the other sensor on the basis of the phase velocity, the group velocity, and the wavelength of the wave. L=Vg×0.5×n×λ/|Vg-Vph| (1)SELECTED DRAWING: Figure 1 |
