Repository logo
 

Search Results

Now showing 1 - 2 of 2
  • Design and evaluation of multi-band RF energy harvesting circuits and antennas for WSNs
    Publication . Borges, Luís M.; Barroca, Norberto; Saraiva, Henrique M.; Tavares, Jorge; Gouveia, Paulo T.; Velez, Fernando J.; Loss, Caroline; Salvado, Rita; Pinho, Pedro; Gonçalves, Ricardo; Carvalho, Nuno Borges; Chavez-Santiago, Raúl; Balasingham, Ilangko
    Radio frequency (RF) energy harvesting is an emerging technology that will enable to drive the next generation of wireless sensor networks (WSNs) without the need of using batteries. In this paper, we present RF energy harvesting circuits specifically developed for GSM bands (900/1800) and a wearable dual-band antenna suitable for possible implementation within clothes for body worn applications. Besides, we address the development and experimental characterization of three different prototypes of a five-stage Dickson voltage multiplier (with match impedance circuit) responsible for harvesting the RF energy. Different printed circuit board (PCB) fabrication techniques to produce the prototypes result in different values of conversion efficiency. Therefore, we conclude that if the PCB fabrication is achieved by means of a rigorous control in the photo-positive method and chemical bath procedure applied to the PCB it allows for attaining better values for the conversion efficiency. All three prototypes (1, 2 and 3) can power supply the IRIS sensor node for RF received powers of -4 dBm, -6 dBm and -5 dBm, and conversion efficiencies of 20, 32 and 26%, respectively. © 2014 IEEE.
  • Textile antenna for RF energy harvesting fully embedded in clothing
    Publication . Loss, Caroline; Gonçalves, Ricardo; Lopes, Catarina; Salvado, Rita; Pinho, Pedro
    In the context of Wireless Body Sensor Networks for healthcare and pervasive applications, textile antennas allow an ubiquitous monitoring, communication, energy harvesting and storage. This paper presents a smart coat with a dual-band textile antenna for Radio Frequency (RF) energy harvesting, operating at GSM 900 and DSC 1800 bands, which is fully embedded in the garment. Results obtained before and after the integration of the antenna into the garment are compared. The gain obtained in the simulation is about 1.8 dBi and 2.06 dBi, with radiation efficiency of 82% and 77,6% for the lowest and highest operating frequency bands, respectively.