Prototype development for application of a rf energy harvester for 2.4ghz band

Radio Frequency Identification is a wireless communication technology which utilizes radio waves to transmit information. This emerging technology has been available for over 50 years yet has only become customary in recent years. For better understanding, the barcode available on groceries items usually serves the same application principle as the RFID. Active or Passive tags are normally associated when dealing with RFID. The major difference of these tags is the presence of an internal battery source. One of the major setbacks in RFID technology is the limitation of the active tag internal battery. Replacement of these batteries usually consumes time and is a hassle. One of the feasible recommendations is to overcome the battery replacement in the RFID tag by harvesting ambient RF waves from surrounding using a RF energy harvester. In the context of this project, the RF energy harvester that is utilized will be a 7-stage Cockroft-Walton rectifier with band pass filters (BPF) and Bessel low pas filter (LPF) integrated on 1.57mm RT/Duroid 5880 (RO5880) laminated thickness operating in 2.45GHz of the transmission medium equivalent to the transmission of the Wi-Fi signal. Since the output energy obtained from the harvester is figuratively low and un-usable. A step –up circuit with charging and storage function will be implemented to produce a more usable energy output. The main component that will be utilized in the proposed design is a power harvesting integrated circuit (IC), LTC 3105. The simulation for the proposed circuit design is done using Linear Technology (LT) Spice Software followed by fabrication of design on to Printed Circuit Board (PCB) using the EAGLE Software. Upon completion of the prototype, the functionality of the prototype was tested under ideal situation where, an output of 5V and 100mA was achieved with a constant supply of 2.45GHz at (-5dBm) which yields and efficiency of 80%.