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. 22, 1996
Filed:
May. 25, 1995
Jack J Schuss, Newton, MA (US);
Peter R Maloney, Norwood, MA (US);
David M Upton, Mont Vernon, NH (US);
Robert J McMorrow, Lincoln, MA (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A Doherty-type power amplifier suitable for satellite telecommunication systems provides linear amplification of noise-like RF signals that have multiple carriers spread over a large instantaneous bandwidth. Efficiencies of 40% to 50% are achieved using PHEMT devices. The power amplifier includes a carrier amplifier that operates a low power levels and a peak amplifier that operates at high power levels. For low power levels, the carrier amplifier delivers its output into twice the optimum load resulting in high efficiency, while the peak amplifier is turned off. At high power levels, both the carrier and the peak amplifier is working into an optimum load and maximum power is delivered. Output matching sections are used to transform the very low optimum load impedance of the PHEMT devices prior to phase shifting and combining.