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:
Mar. 30, 1999
Filed:
Nov. 07, 1996
Karl W Rabe, Chapel Hill, NC (US);
Ericsson, Inc., , US;
Abstract
A radiotelephone having an acoustical wave guide for channeling and directing sound energy into a microphone forming a part of the radiotelephone. The wave guide includes an elongated tube structure that varies in cross-sectional area from an inlet end to an outlet end thereof. More particularly, the wave guide is formed by a wall structure that includes portions that assume a wave configuration. This wave configuration gives rise to the varying cross-sectional area that is repeatedly found between the inlet and outlet end portions of the wave guide. This wave type configuration for the wave guide forms an acoustical low-pass filter that propagates and transmits non-resonant low frequencies in the range of 300 Hz to 3,000 Hz.