Exploitation of Multi-sine Intermodulation for Passive Backscattering UWB Localization

This paper proposes the use of multi-sine UHF excitation for rectenna applications not only for the well-known possible improvement of rectification performance in energy harvesting, but also for exploiting the same rectifier to enable high-accuracy localization of the tag by backscattering higher order harmonics usually wasted and unwanted. This twofold goal is obtained through the design of an extremely simple dual-mode RFID tag, exploiting the multi-sine UHF excitation to harvest energy, and the UWB signal, generated for free and consisting of the higher intermodulation products, to communicate with the readers for the tag itself localization. Both modeled and measured results demonstrate the excellent dual-mode performance, despite of the limited add-on circuitry if compared to other tags architectures combining energy harvesting and localization capabilities.