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:
Jul. 27, 1999
Filed:
Sep. 30, 1996
Mark J Dapper, Cincinnati, OH (US);
Michael J Geile, Loveland, OH (US);
Barry Walter Carlin, Greenhills, OH (US);
USA Digital Radio Partners, L.P., Columbia, MD (US);
Abstract
An apparatus and method for generating a broadcast waveform is provided which, for generating an in-phase component, includes an in-phase digital signal generator; a first filter for filtering the in-phase digital signal; a first digital-to-analog converter for converting the filtered digital signal into a first analog signal; an AM baseband signal generator producing an AM baseband signal; a first summer for summing the first analog and AM baseband signals to produce a composite analog signal; and a first modulator for modulating the composite analog signal with a first carrier signal at a transmission frequency, thus producing a first modulated signal. To provide the quadrature component of the broadcast waveform, the waveform generator includes a quadrature digital signal generator producing a quadrature digital signal; a second digital-to-analog converter for converting the quadrature digital signal into a second analog signal; a second modulator for modulating the second base-band signal with a second carrier signal; and a second summer for summing the first and second modulated signals, thus producing the broadcast waveform. The apparatus improves the signal-to-noise ratio in analog AM receivers, especially at higher frequencies.