Georgia Tech Research Corporation

University of Rome Tor Vergata

Polaris Wireless, Inc.

Thingamagigwerks, LLC

Gregory David Durgin

Francesco Amato

Cheng Qi

Bernard Kippelen

Yenpao Albert Lu

Matthew Trotter

Andrew F Peterson

Gregory Koo

Azhar Hason

Systems and methods for radiolocation using backscatter RFID tags and a special-purpose reader that produces a SFCW RF interrogation signal comprising N carrier frequencies. A backscattered interrogation signal from a backscatter RFID tag is down-converted using at least a portion of the generated SFCW RF interrogation signal. RSP corresponding to the N carrier frequencies are determined. RSS may be determined to improve performance. A distance between the RFID reader and the backscatter RFID tag may be estimated based on at least a summation of differences between RSPs corresponding to adjacent carrier frequencies.

Systems and methods for RFID positioning

Systems and methods are disclosed for radiolocation using backscatter RFID tags and a special-purpose reader that produces a stepped-frequency continuous wave (SFCW) radio frequency (RF) interrogation signal comprising N carrier frequencies. A backscattered interrogation signal from a backscatter RFID tag is down-converted using at least a portion of the generated SFCW RF interrogation signal. Received signal phases (RSP) corresponding to the N carrier frequencies are determined. Received signal strength (RSS) may be determined to improve performance. A distance between the RFID reader and the backscatter RFID tag may be estimated based on at least a summation of differences between RSPs corresponding to adjacent carrier frequencies.

A system () and method () for determining the location of an object is provided. A plurality of radio transceivers () are disposed about a location of interest (). One or more tags () are coupled to an object. The radio transceivers () transmit radio frequency signals () to the tag (), which backscatters a return signal () having a unique identifier modulated therein due to a switch () switching between two or more loads () in accordance with a unique identification code (). A location determination module () then determines the location of the tag () by using a course location estimate (), a fine location estimate (), or combinations thereof. A object modeling module () can create multidimensional models using the locations of the tags ().

Method and apparatus for location determination using reflected interferometry

A multi-antenna signaling scheme, system and method for passive or low-powered RF devices, such as a radio frequency identification tag, are herein described. In one embodiment, the presently disclosed subject matter discloses a Retrodirective Array Phase Modulator which is configured to allow RFID tags to return higher-powered signals with higher data rates back to an RFID interrogator or reader unit. In some configurations, pattern strobing is used which is an array-based transmission technique for stepping or sweeping an RF waveform through space so that passive radio devices may more efficiently harvest energy without increasing transmit power. In some configurations, the presently disclosed subject matter may also use a Staggered Pattern Charge Collector to boost the collection of microwave power.

Multi-antenna signaling scheme for low-powered or passive radio communications

The present invention describes systems and methods for providing a power optimized waveform. An exemplary embodiment of the present invention provides a method of powering wirelessly powered devices including the step of providing a wirelessly powered device and a wireless power transmission system. Furthermore, the method involves receiving a power waveform to the wirelessly powered device from the wireless power transmission system, wherein each cycle of the power waveform includes a charge portion and a starve portion. Additionally, the maximum voltage of the charge portion is at least double the Root Mean Square ('RMS') voltage of the starve portion.

Systems and methods for providing a power optimized waveform

Various sensors, systems, and methods for monitoring environmental conditions are provided. In one embodiment, among others, a passive sensor includes an antenna; a modulating circuit coupled to the antenna by a microstrip transmission line, the modulating circuit capable of modulating a backscattered signal; a sensing material disposed between the microstrip transmission line and a ground plane of the passive sensor, where an electrical property of at least a portion of the sensing material varies with the environmental condition; and where the modulated backscattered signal includes at least one of phase and amplitude information corresponding to the electrical property of the portion of the sensing material.

Passive environmental sensing

Embodiments according to the present invention comprised RFID tags comprised of components disposed on a flexible conformal substrate. The substrate may be substantially transparent or opaque and the components may be comprised of organic electronic components. Components and circuits may be manufactured using thin-film deposition processes or by deposition of metal-containing inks using inkjet technology. Exemplary use of an embodiment according to the present invention is as a component in an on-vehicle radio-frequency (RF) automated toll system.

Thin flexible radio frequency identification tags and subsystems thereof

A generalized framework is disclosed in which a wide variety of propagation models can be cast in a matrix-based format using arbitrary matrix coefficients. Casting propagation models in the matrix-based framework enables efficient computer implementation and calculation, ease of tuning, admissibility, and aggregating multiple propagation models into a single matrix-based model. Matrix-based propagation models based on transmitter-receiver azimuth orientation, transmitter antenna height, terrain elevation, and clutter are also disclosed. The propagation models can be used in conjunction with automated data acquisition from information sources such as topographic maps, clutter maps, etc.

Growing community of inventors

Atlanta, GA, United States of America

Gregory David Durgin