Harvesting for Scattering RF-Signals receivable by Mobile Telephones

This work studies RF energy harvesting as a power supply for wireless (back-)scattering technology in the 2.4 GHz ISM Band. The scattering is accomplished by modulating an incident continuous wave signal (CW) according to an intermediate signal such that the modulated signal is receivable by a Bluetooth Low Energy (BLE) receiver. The intermediate signal provides for frequency shifting as well as information carrying modulation and is specifically designed as a signal with a relative low frequency of ca. 4 MHz, which allows for signal generation by a low energy microcontroller. The microcontroller receives its operational energy from a harvesting circuit, which accumulates and intermediately stores the energy of the incident CW signal. We achieved unidirectional BLE advertising by combining scattering technology and energy harvesting and thus showed the feasibility of wireless communication from a battery-less RF scattering transponder to a regular mobile telephone.