ACOUSTICAL ARRAY FOR PHASE CONJUGATION

摘要

Acoustical phase conjugation is a technique that permits to reverse precisely the direction of propagation and the overall phase factor for each plane wave in arbitrary beam of acoustical wave with the aid of a phase conijugate mirror. A phase conijugate mirror is a system able to reproduce, mechanically, a "time reversed " wave front". A beam emitted by an array S1 is reflected, refracted and generally distorted by an obstacle O. This beam is received and reflected by a phase conjugator S2, retraces its original path and is received by S1. In S1 is possible comparing the signals emitted and the signals received. The comparison gives the map of the attenuation in O along the path of the beam.