Compact resonator on leather for nonradiative inductive power transfer and far‐field data links

Abstract

In this paper, a wearable resonator suitable to be used for both power and data transmission is presented. The basic element is a complementary split ring resonator that has been optimized to operate both as a dipole‐like antenna at 2.45 GHz and as the receiver of a resonant energy link operating at 915 MHz when coupled with an identical external resonator connected to a power source. Experimental data referring to a prototype fabricated by using a conductive adhesive fabric on a leather substrate are reported and discussed. With regard to the wireless resonant energy link (WREL), it is demonstrated that at 915 MHz, the RF‐to‐RF power transfer efficiency of the link is approximately 78.1%. As for the performance obtained when the resonator is used as an antenna, a gain of approximately −0.43 dB was obtained. Additionally, the performance of the proposed link when connected to a Power Management Unit (PMU) that converts the radio frequency (RF) energy received by the wearable resonator into DC energy that can be directly used for recharging a thin‐film battery was also investigated. Experimental tests were performed in order to evaluate both the total efficiency of the wireless charger (i.e., the WREL link connected to the PMU) and the time necessary to recharge a THINERGY MEC201 battery. The obtained results demonstrate the feasibility of using the proposed WREL for implementing a battery charger; in particular, by providing an input power higher than 8 dBm, the time necessary to recharge the considered thin‐film battery is shorter than 38 min.

Wearable Antennas for Remote Health Care Monitoring Systems

“…Furthermore, Figures 6(c) and 6(d) show the photographs of two wearable resonators proposed for power transfer applications in [38,39], respectively. These results demonstrate that the proposed manufacturing technique can be exploited for fabricating circular and elliptical loops/geometries.…”

Durability of Wearable Antennas Based on Nonwoven Conductive Fabrics: Experimental Study on Resistance to Washing and Ironing

“…As per the substrate, it is possible to employ materials that are typically used in the clothing industry, such as cotton, jeans, and pile, while, for implementing the conductive parts of the antenna, the use of different materials has been proposed and tested in the literature . Among these, particularly attractive are (i) nonwoven conductive fabrics (NWCFs) [12][13][14][15][16][17][18], (ii) conductive threads [19][20][21][22][23][24][25][26][27], and (iii) electrotextiles [28][29][30][31][32][33].…”