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:
Nov. 26, 2002
Filed:
Aug. 14, 2001
Dan Nobbe, Crystal Lake, IL (US);
Dale Schwent, Schaumburg, IL (US);
David P. Kovac, Vernon Hills, IL (US);
Vikram Karnani, Chicago, IL (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A low noise direct conversion transmitter architecture without a post-PA filter is described. A high power/low noise differential LO ( ), controlled by a near unity divide ratio PLL ( ) for re-modulation protection, is coupled a polyphase quadrature generator ( ) generating amplitude-balanced and phase-shifted limited differential LO signals. The quadrature mixers ( and ) receive the limited differential LO signals and the filtered differential baseband signals to produce up-converted differential signals. The combiner ( ) receives the up-converted differential signals and combines them to produce a differential RF transmission signal. A VCA ( ) amplifies the differential RF transmission signal, and the resulting differential signal is converted to a single-ended RF transmission signal through a balun ( ). A linear amplifier ( ) is coupled to the single-ended RF transmission signal for amplification before radio transmission by an antenna ( ).