Invention Grant
- Patent Title: Method and apparatus for reduced noise and carrier feedthrough in multimode transmitter
- Patent Title (中): 多模发射机减少噪声和载波馈通的方法和装置
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Application No.: US11421200Application Date: 2006-05-31
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Publication No.: US07688880B2Publication Date: 2010-03-30
- Inventor: David Ryan Haub , Daniel Neil Ralston
- Applicant: David Ryan Haub , Daniel Neil Ralston
- Applicant Address: KY George Town, Grand Cayman
- Assignee: Spreadtrum Communications Inc.
- Current Assignee: Spreadtrum Communications Inc.
- Current Assignee Address: KY George Town, Grand Cayman
- Main IPC: H04B1/00
- IPC: H04B1/00

Abstract:
A high dynamic range low noise direct conversion transmitter within a multimode apparatus having multiple transmit and receive operating modes is described. The direct conversion transmitter can include a digital baseband coupled to a low noise direct conversion stage. A high dynamic range current folding digital to analog converter can be used to convert the digital baseband signals to analog representations. A wide dynamic range variable gain baseband amplifier couples the baseband signal to the direct conversion stage. A controllable passive attenuation stage operates to provide further gain control. Carrier feedthrough can be substantially eliminated using a carrier feedthrough cancellation loop that selectively utilizes one of a plurality of receivers configured for one of the multiple receive modes.
Public/Granted literature
- US20070280338A1 METHOD AND APPARATUS FOR REDUCED NOISE AND CARRIER FEEDTHROUGH IN MULTIMODE TRANSMITTER Public/Granted day:2007-12-06
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