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Wireless Autonomous Device Data Transmission

Detailed Technology Description

None

*Abstract

BackgroundA wireless autonomous device (WAD) is an electronic device that has no on board battery or wired power supply. WADs are powered by receiving radio frequency (RF) energy that is either directed toward them (a directed source) or is ambient and converting the received RF energy into a direct current (DC) voltage. The DC voltage is used to power on-board electronics, such and a microprocessor and/or sensing circuitry, and an RF transmitter which communicates information, such as a sensor reading, to a remote receiver, commonly referred to as a base station. WADs are employed in a number of fields, such as radio frequency identification (RFID) systems (wherein the WADs are radio frequency tags or transponders), security monitoring and remote sensing, among others. WADs are particularly desirable in certain applications as they have essentially an infinite shelf life and do not require wiring because they are powered by RF energy transmitted through the air. The transmission of data from a WAD to a base station is a major draw on the power of the WAD. In some applications, this power draw represents a major limiting factor. If the amount of power transmitted can be reduced, the range of a WAD can be greatly extended. TechnologyThis invention relates to wireless autonomous devices (WAD), and in particular to the transmission of data from wireless autonomous devices to a base station in a manner that conserves power. The WAD has a data element having a predetermined profile that has a total number of sequenced possible data element combinations. The method includes receiving at the WAD an RF profile transmitted by the base station that includes a triggering portion having a number of pulses, wherein the number is at least equal to the total number of possible data element combinations. The method further includes keeping a count of received pulses and wirelessly transmitting a piece of data, preferably one bit, to the base station when the count reaches a value equal to the stored data element's particular number in the sequence. Finally, the method includes receiving the piece of data at the base station and using the receipt to determine which of the possible data element combinations the stored data element is.

*Principal Investigator

Name: James Cain, Professor

Department: Electrical and Computer Engineering

Name: Minhong Mi

Department: Electrical and Computer Engineering

Name: Marlin Mickle, Professor of Electrical Engineering

Department: Electrical and Computer Engineering

Name: David Sammel

Department: Electrical and Computer Engineering

Country/Region

USA