Feasibility of wireless sensors using ambient 2.4GHz RF energy

We present a new system for measuring ambient RF energy in the 2.4GHz ISM band. This apparatus is intended to establish the feasibility of harvesting ambient RF energy to power emerging ultra-low-power sensors and microcontrollers. We simultaneously acquire RF measurements from a spatial and polarization diversity antenna system, with both a spectrum analyzer (frequency-selective but slow), and a log amp (wideband but fast), explain key tradeoffs in the measurement configuration, and present a post-processing algorithm which provides a reliable characterization of the RF energy available in the 2.4GHz ISM band. Preliminary results suggest enough energy is available to support a low duty cycle wireless sensor node system. An average RF power of 11nW is observed 10m away from a typical Wi-Fi access point in an office environment, suggesting the possibility of low duty cycle, wirelessly powered sensing and communication using a Bluetooth Low Energy (BLE) or another ultra low power uplink.

[1]  G.D. Durgin,et al.  Complete Link Budgets for Backscatter-Radio and RFID Systems , 2009, IEEE Antennas and Propagation Magazine.

[2]  J.A.C. Theeuwes,et al.  Ambient RF Energy Scavenging: GSM and WLAN Power Density Measurements , 2008, 2008 38th European Microwave Conference.

[3]  Mohamed Latrach,et al.  Ambient RF Energy Harvesting , 2010 .

[4]  Martin Fischer,et al.  Fully integrated passive UHF RFID transponder IC with 16.7-μW minimum RF input power , 2003, IEEE J. Solid State Circuits.

[5]  Anantha Chandrakasan,et al.  Platform architecture for solar, thermal and vibration energy combining with MPPT and single inductor , 2011, 2011 Symposium on VLSI Circuits - Digest of Technical Papers.

[6]  Joseph A. Paradiso,et al.  Energy scavenging for mobile and wireless electronics , 2005, IEEE Pervasive Computing.

[7]  A. M. Abdullah,et al.  Wireless lan medium access control (mac) and physical layer (phy) specifications , 1997 .

[8]  Joshua R. Smith,et al.  Experimental results with two wireless power transfer systems , 2009, 2009 IEEE Radio and Wireless Symposium.

[9]  Gregory D. Abowd,et al.  Design and Performance of an Optimal Inertial Power Harvester for Human-Powered Devices , 2011, IEEE Transactions on Mobile Computing.

[10]  Tadahiro Kuroda,et al.  A battery-less WiFi-BER modulated data transmitter with ambient radio-wave energy harvesting , 2011, 2011 Symposium on VLSI Circuits - Digest of Technical Papers.

[11]  Taeseung D. Yoo,et al.  Generating Electricity While Walking with Loads , 2022 .