Method of generating spherical waves in ultrasonic range

摘要

The ultrasonic wave from a transmitter (1) is compressed by ambient effects up to a single mode waveguide, at whose end the ultrasonic wave is delivered into free space as a spherical wave. Pref. the compression is carried out slowly and continuously. Next to the ultrasonic transmitter, in the transmit direction, is located a funnel (2), whose end opens into a tube (3) with a dia. in the order of 10 wavelengths of the transmitted ultrasonic wave. The tube can be replaced by another suitable waveguide.