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:
Jun. 29, 1999
Filed:
Oct. 02, 1997
Frank Chethik, Palo Alto, CA (US);
Paul Schwartz, Richardson, TX (US);
Lockheed Martin Corporation, Bethesda, MD (US);
Abstract
A modulating array transmitter employing a method that provides for improved power efficiency. The present inventors have observed that for symbols where pairs of power amplifiers of the modulating array transmitter are driven with opposing phases, the pairs of power amplifiers may both be keyed off to conserve prime power. The transmitter has a lookup table for providing a plurality of digital input signals and an on/off keying bit input signal, a plurality of quadraphase power elements that each comprise a modulator coupled to the lookup table and to a reference signal source, and a high efficiency amplifier coupled to a power source. A power combiner combines outputs of the plurality of power elements to produce a quadrature amplitude modulated (QAM) output constellation containing a plurality of symbols. The on/off keying bit input signal is used to key off selected pairs of power amplifiers that are driven with opposing phases and produce certain of the symbols of the constellation. When the selected pairs of power amplifiers are keyed off, prime power provided to the amplifiers of the transmitter is conserved.