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:
Mar. 02, 2004
Filed:
Jan. 28, 2002
Raymond Sydney Pengelly, Hillsborough, NC (US);
Cree Microwave, Inc., Sunnyvale, CA (US);
Abstract
An RF power amplifier for amplifying an RF signal over a broad range of power with improved efficiency includes a main amplifier for amplifying an RF signal over a first range of power and with a power saturation level below the maximum of the broad range of power. A plurality of auxiliary amplifiers are connected in parallel with the main amplifier with each of the auxiliary amplifiers being biased to sequentially provide an amplified output signal after the main amplifier approaches saturation. The input signal is applied through a signal splitter to the main amplifier and the plurality of auxiliary amplifiers, and an output for receiving amplified output signals from the main amplifier and the plurality of auxiliary amplifiers includes a resistive load R/2. The split input signal is applied through a 90° transformer to the main amplifier, and the outputs of the auxiliary amplifiers are applied through 90° transformers to a output load. When operating below saturation, the main amplifier delivers power to a load of 2R and the main amplifier delivers current to the load which is one-half the current at maximum power and the amplifier is saturated.