TRANSDUCTEUR ACOUSTIQUE MULTIFREQUENCES A LARGES BANDES

• Main Authors: LE VERRIER BERTRAND, TARDY BRUNOD, RAMOS ALPHONSE, ROUX GERARD
• Format: Patent
• Language: French
• Published: 14.08.1996
• Edition: 6
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DEAF-AID SETS; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; DIAGNOSIS; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; FOR PERFORMING MECHANICAL WORK IN GENERAL; GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL; HUMAN NECESSITIES; HYGIENE; IDENTIFICATION; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKEACOUSTIC ELECTROMECHANICAL TRANSDUCERS; MEASURING; MEDICAL OR VETERINARY SCIENCE; METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICALVIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY; PERFORMING OPERATIONS; PHYSICS; PUBLIC ADDRESS SYSTEMS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; SURGERY; TESTING; TRANSPORTING

PCT No. PCT/FR95/00800 Sec. 371 Date Jan. 6, 1997 Sec. 102(e) Date Jan. 6, 1997 PCT Filed Jun. 16, 1995 PCT Pub. No. WO96/01702 PCT Pub. Date Jan. 25, 1996The invention relates to multifrequency acoustic transducers exhibiting a wide band around each resonant frequency. It consists in inserting between a lambda /2 active emitter plate (201) and the soft reflector (203) which supports it a rear plate (202) resonating in lambda /4 mode and in placing on this active plate two marcher plates (204, 205) whose impedances are designed so as to best match the two frequencies obtained by inserting this rear plate. Thicknesses of these marcher plates are optimized with the aid of a model of for example Mason type starting from a value close to lambda /4 for the frequency to be matched. It makes is possible to construct sonar transducers which operate equally well in detection mode and in classification mode.