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. 02, 1999
Filed:
Aug. 15, 1997
Frank Chethik, Palo Alto, CA (US);
Lockheed Martin Aerospace Corp., Bethesda, MD (US);
Abstract
A high power RF transmitter that uses high power modulators that perform quadrature amplitude modulation (QAM) on a carrier signal after power amplification that is performed in the RF carrier source. The present invention transposes the locations of the modulators and power amplifier, and thus directly modulates a high power carrier signal. An RF carrier source generates a high power RF carrier signal that is split by a power splitter. A lookup table containing 2.sup.B words by K bits receives transmit data and mapping data and generates K-tuple modulating data. A plurality of phase key modulators are respectively coupled to outputs of the power splitter and to the lookup table and phase key modulate each of the signal components of the carrier signal using the K-tuple modulating data. A power combiner is coupled to outputs of the phase key modulators for outputting a high power QAM constellation from the transmitter.