High Efficient Passive Localization Exploiting Harmonic RFID Tags

This contribution shows the exploitation of multi-sine excitations of UHF rectennas for high accuracy localization, based on the intermodulation products to passively generate an output UWB signal. The objective is reached by a concurrent circuit (for intermodulation products optimization) and system (for accurate localization) design of a novel architecture based on two readers and a number of tags. At the rectifier output two paths are derived: one in DC which plays the common role of delivering the converted DC power to an optimum load; one wideband with the role of collecting the low-power higher harmonics generated by the rectifier, under multi-sine excitations, to be used as an ultra-wideband radiated signal. Such signal is used for communicating with the receivers for localization purposes. Analytical, numerical and experimental results will be provided demonstrating very satisfactory performance obtained from such a fully passive circuit.