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:
Feb. 24, 2015
Filed:
Mar. 02, 2012
Joakim Eriksson, Lund, SE;
Jonny Strandh, Höör, SE;
Joakim Eriksson, Lund, SE;
Jonny Strandh, Höör, SE;
Sony Corporation, Tokyo, JP;
Sony Mobile Communications AB, Lund, SE;
Abstract
The invention is directed to echo cancellation for a microphone system. An exemplary microphone system comprises a first transistor, wherein a gate terminal of the first transistor is connected to a ground terminal via a microphone electret element, the microphone electret element being associated with a capacitance and a voltage, the microphone electret element reverse biasing the first transistor; and a second transistor in parallel with the first transistor, wherein a gate terminal of the second transistor is connected to the ground terminal via a capacitor, the capacitance of the capacitor being selected to suppress at least a portion of a common mode signal, and wherein the gate terminal of the second transistor is not connected to the microphone electret element. The common mode signal comprises the echo, which may be the output of a speaker system that is received as input to the microphone system.