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:
Dec. 23, 1997
Filed:
Jun. 05, 1996
Juha Pikkarainen, Oulu, FI;
Veijo Kontas, Oulu, FI;
Nokia Mobile Phones Ltd., Salo, FI;
Abstract
A method and modulator for modulating a digital signal to an analog intermediate-frequency signal. A baseband digital signal (I, Q) is taken to a digital-to-analog converter (71, 710) in which it is sampled at a certain sampling frequency (f.sub.in) and converted to an analog signal. The conversion produces a baseband signal (f.sub.sig) and signals (N*f.sub.in, f.sub.Ni) at multiples of the sampling frequency (f.sub.in). The sampling frequency is increased, advantageously according to a sigma-delta D/A conversion, and one of the signals (N*f.sub.in,f.sub.Ni) at multiples of the sampling frequency (f.sub.in), produced by the conversion, is selected as the output signal (f.sub.IF), advantageously a multiple (N*f.sub.in, f.sub.Ni) of the sampling frequency that is directly at the intermediate frequency or transmission frequency.