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:
Oct. 09, 2001
Filed:
Feb. 25, 1999
Atsushi Shinoda, Sagamihara, JP;
Kenichi Shiraishi, Yokohama, JP;
Kabushiki Kaisha Kenwood, Tokyo, JP;
Abstract
The present invention provides an AM modulated wave eliminating circuit which is capable of extracting a digital modulated wave by cancelling an AM modulated wave from an AM data multiplex modulated wave. A composite wave is composed of an AM carrier wave in-phase signal, an AM carrier wave reverse-phase signal and a digital modulated wave is extracted from an AM data multiplex modulated wave composed of an AM stereo modulated wave multiplexed with a digital modulated wave within the same frequency band, values corresponding to different phase deflection angles of an AM stereo output from a phase level generator (,) are multiplied by the AM carrier wave in-phase signal with multipliers (,through,), multiplication outputs are added to the composite wave with adders (,through,), a phase deflection angle corresponding to an output at a minimum level out of addition outputs is determined with a phase presumer (,), a value corresponding to a determined phase deflection angle is selected from an output of a phase level generator (,) with a phase level selector (,), a selected value is multiplied by an AM carrier wave in-phase signal component with a multiplier (,), a multiplication output is added to the composite wave with an adder (,) and an addition output is used as a digital modulated wave.