07652577 is referenced by 146 patents and cites 29 patents.

Systems and methods for beamforming in radio frequency identification (RFID) applications are disclosed. A beamforming system uses a distributed architecture and techniques for antenna beamforming using a feedback control loop to direct radio frequency (RF) energy onto a specific region, referred to as an interrogation zone, which includes a calibration node where one or more RFID tags may be located. The distributed architecture of the beamforming system is resistant to fading and shadowing effects, providing accurate RFID reader operation even in environments with multi-path reflections or environmental changes, such as people moving around or changes in the location of equipment.

Title
Systems and methods of beamforming in radio frequency identification applications
Application Number
11/702980
Publication Number
7652577 (B1)
Application Date
February 5, 2007
Publication Date
January 26, 2010
Inventor
Kannan Ramchandran
El Cerrito
CA, US
Ben J Wild
Oakland
CA, US
Upamanyu Madhow
Santa Barbara
CA, US
Agent
Caesar Rivise Bernstein Cohen & Pokotilow
Assignee
Checkpoint Systems
NJ, US
IPC
G08B 13/14
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