Ambient energy harvesting from a two-way talk radio for flexible wearable devices utilizing inkjet printing masking

In this paper, the design, on a flexible LCP substrate, and fabrication process of a wearable circuit harvesting the ambient energy emitted from a two-way radio is discussed in detail.The circuit is fabricated through the combination of circuit traces made with masking utilizing inkjet printing technology and lumped circuit components. The input power for the RF-DC conversion circuit is analytically computed from the measured S-parameters of the Tx-Rx propagation channel. A maximum output power of 43.2mW with the RF-DC conversion efficiency of 82.5% and open- circuit voltage of 17.87 V is achieved with an E-field energy harvester placed 7cm away from an off-the-shelf 1W two-way talk radio.