Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.