P2F-8 Multipath Interference Between Plane and Corner Reflection for Ultrasonic Ranging Systems

In this paper, we study the multipath interference between the plane and corner reflections for 40 kHz ultrasonic transducers with 55deg beam angle moving along or transverse to the transmitting/receiving directions. Discrete spots of low echo signal were found for either transducer moving directions. The interference pattern is similar to the diffraction pattern of a wave passing through an aperture that disrupts the wave. When a destructive or constructive interference happens, there is integer number of half wave length difference between the plane and corner reflection path distances.