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. 13, 2001
Filed:
Oct. 19, 1998
Peter S. Rha, Richardson, TX (US);
Abstract
A digital feedforward (FF) amplifier system is disclosed for use in an RF transmission system. The digital FF amplifier uses digital signal processing to generate error correction signals that reduce intermodulation distortion caused by saturation of the main power amplifier. The digital signals in the improved FF amplifier may be buffered, if necessary, thereby eliminating the need for delay lines. A main amplification branch includes a digital combiner for summing input digital signals, digital-to-analog converters, RF modulation circuitry and a main power amplifier. An error correction signal branch includes an error correction signal generator, digital-to-analog converters, and RF modulation circuitry. The RF outputs of the main amplification branch and the error correction signal branch are combined to produce an RF output signal with reduced distortion. Optionally, an amplifier characterization branch may be included comprising RF output feedback circuitry and an amplifier model. The amplifier model updates the error correction generator with time varying characteristic information about the main power amplifier.