The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 27, 1984
Filed:
Mar. 03, 1982
Tuan K Duong, Elancourt, FR;
Emmanuel Lefort, Montigny le Bretonneux, FR;
Maurice G Bellanger, Paris, FR;
Abstract
An electroacoustic transducer apparatus which prevents oscillations as a result of acoustic coupling between an acoustic-wave transmitter and a receiver. The transmitter and receiver each comprise an electro-acoustic transducer network. The transducers in each network are arranged so that the phase and amplitude of the signals applied to the transmitter transducers and the signals supplied to an adder circuit by the receiver network transducers (25) to (30) of the receiver network are such that in the oscillation frequency band the radiation pattern of the transmitter network and the directivity pattern of the receiver network are zero in at least one direction. The two networks are arranged relative to each other so that the directions of minimum radiation and directivity correspond to the directions of maximum coupling between the transducers of the two networks.