Abstract: A method and system for estimating position of a moving RFID tag is provided. The method includes transmitting at least one interrogator signal; receiving, at an interrogator antenna, a reflected signal from the RFID tag; determining phase changes of the reflected signal with respect to the phase of the at least one interrogator signal; weighting the phase changes based on instant power corresponding to the phase changes; producing a phase trajectory for the reflected signal based on the weighted phase changes; and estimating position of the RFID tag relative to the interrogator antenna based on the peak of the phase trajectory for the reflected signal.

Abstract: A method and system for estimating position of a moving RFID tag is provided. The method includes transmitting at least one interrogator signal; receiving, at an interrogator antenna, a reflected signal from the RFID tag; determining phase changes of the reflected signal with respect to the phase of the at least one interrogator signal; weighting the phase changes based on instant power corresponding to the phase changes; producing a phase trajectory for the reflected signal based on the weighted phase changes; and estimating position of the RFID tag relative to the interrogator antenna based on the peak of the phase trajectory for the reflected signal.

Abstract: A method of detecting position of a moving RFID tag relative to an antenna, includes continually receiving a signal from the RFID tag at the antenna. The phase of the received signal over a time period is detected and, based on a maximum detected phase, the position of the RFID tag relative to the antenna is detected.