Research on Anti-eavesdropping System of Multi-Source Ultrasonic in Space

The invention relates to a space multi-sound source ultrasonic anti-eavesdropping system, which is a method for preventing illegal eavesdropping by using a plurality of ultrasonic generators to generate interference ultrasonic beams in space. Compared with the planar ultrasonic anti-eavesdropping system, the spatial multi-sound source ultrasonic anti-eavesdropping system has higher flexibility and adaptability in the diversity of generating ultrasonic beams and the coverage of the target area. The basic principle of the spatial multi-sound source ultrasonic anti-eavesdropping system is to use multiple ultrasonic generators to generate ultrasonic beams that interfere with each other in space, so as to form a complex sound field. This sound field can cover the target area and interfere with the eavesdropping equipment in the area. The preliminary results show that when the angle between two ultrasonic sound sources is set to 60 °, the measured interference signal strength on the central connecting line will still maintain 70% of the signal strength in the main direction of the sound source, and the eavesdropping recording distance that can be effectively blocked will still remain more than 2 meters. Keywords-anti-eavesdropping, ultrasonic beams, spatial intensity