United States Patent 7,565,117
Sugar , et al. July 21, 2009
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Control of power amplifiers in devices using transmit beamforming
Abstract
A transmitter comprises a plurality of transmit antennas for simultaneously transmitting weighted signals according to a channel transfer function. Each antenna has a corresponding amplifier that is bias controlled according to the transmit weights derived for the antenna transmission. A baseband processor produces digital weighted signals for upconversion and amplification by the amplifiers. Each amplifier is accompanied by a bias circuit responsive to the transmit weights. Alternatively, or additionally, corresponding DC/DC converters are used to control the operating voltage of the amplifiers.
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Inventors: Sugar; Gary L. (Rockville, MD), Vaidyanathan; Chandra (Bethesda, MD), Lou; Sifen (Potomac, MD)
Assignee: IPR Licensing, Inc. (Wilmington, DE)
Appl. No.: 11/326,630
Filed: January 6, 2006
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Related U.S. Patent Documents
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Application Number Filing Date Patent Number Issue Date
10867249 Jun., 2004 6993299
10249063 Mar., 2003 6871049
60365811 Mar., 2002
60365775 Mar., 2002
60365797 Mar., 2002
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Current U.S. Class: 455/103
Current International Class: H04B 1/04 (20060101)
Field of Search: 455/101,103,105,127.1,127.2,522,550.1,561,562.1
