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All Digital Ambient Backscatter System

Torres, R. ; Correia, R. ; Carvalho, N.B.C.

All Digital Ambient Backscatter System, Proc IEEE Wireless Power Transfer Conference, Seul, Korea, South, Vol. , pp. - , November, 2020.

Digital Object Identifier: 10.1109/WPTC48563.2020.9295547

This work presents an all digital ambient backscatter system which operates with ambient FM sources. Moreover, the system uses commercial modules to perform backscatter and has the ability of using Wi-Fi and Bluetooth signals. The backscatter module presented here uses an ESP32 MCU and a telescopic monopole as an antenna. The variation of a digital IO pin at 5 kHz causes an impedance variation in the connected antenna reflecting the incoming FM waves with an ASK modulation and can be demodulated by a low-cost RTL-SDR USB dongle. In this work an all digital backscatter communication system was shown by using an ambient FM signal from a station at a distance of 3 Km which was decoded with success. With this system it is possible to reduce the complexity of a low power communication system, the number of sensors batteries and the number of dedicated transmitters, that proves to be a low-cost and environmentally friendly solution.