07400253 is referenced by 79 patents and cites 8 patents.

A system and device for harvesting various frequencies and polarizations of ambient radio frequency (RF) electromagnetic (EM) energy for making a passive sensor (tag) into an autonomous passive sensor (tag) adapted to collect and store data with time-stamping and some primitive computation when necessary even when an interrogating radio frequency identification (RFID) reader is not present (not transmitting). A specific source of ambient RF EM energy may include wireless fidelity (WiFi) and/or cellular telephone base stations. The system and device may also allow for the recharging of energy storage units in active and battery assisted passive (BAP) devices. The system could be a “smart building” that uses passive sensors with RF EM energy harvesting capability to sense environmental variables, security breaches, as well as information from “smart appliances” that can be used for a variety of controls and can be accessed locally or remotely over the Internet or cellular networks.

Title
Harvesting ambient radio frequency electromagnetic energy for powering wireless electronic devices, sensors and sensor networks and applications thereof
Application Number
11/459459
Publication Number
7400253 (B2)
Application Date
July 24, 2006
Publication Date
July 15, 2008
Inventor
Marc H Cohen
Silver Spring
MD, US
Agent
Gibb & Rahman
Mohammad S Rahman Esq
Assignee
MHCMOS
MD, US
IPC
G08B 13/14
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