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:
Oct. 12, 1999
Filed:
Nov. 25, 1997
James D Thompson, Manhattan Beach, CA (US);
Hughes Electronics Corporation, El Segundo, CA (US);
Abstract
Amplifier-induced intermodulation distortion (IMD) is reduced by encoding a multi-frequency input composite signal into multiple encoded signals that vary from each other in their power amplitudes as a function of frequency, amplifying the encoded signals, and then decoding them in a complementary fashion so as to differentiate between the amplified signal components and the IMD components. The amplified signal components are coherently combined to separate them from the IMD components, which are incoherently combined. The input signal is preferably encoded by dividng it into multiple divided signals, introducing relative phase shifts between the divided signals that vary as a function of frequency, and combining the divided and phase shifted signals with each other in a Butler matrix prior to amplification. The phase shifts are introduced by means of time delays that are preferably equal to integer multiples of 4.PI. divided by the input signal bandwidth.