RF Energy Harvesting using 2 × 4 Circular Microstrip Array Antenna for 5G-IoT Zero Power Wireless Sensors

The advent of the Internet of Things (IoT) has transmogrified pervasive computing with multitude of applications built upon heterogeneous devices. With a capacity of allowing 50,000 nodes (IoT device sensors) to be present in a single cell, 5G-IoT demands uninterrupted wireless power supply to nodes in order to reduce design complexity and cost. The Wireless Power Transfer (WPT) rectennas are a solution to such needs. The rectenna is hence designed to power up devices in its vicinity using circular microstrip patch antenna array. At the receiving end, the received signal is converted to a DC supply using rectifier circuits, from where the power is given to the sensors(nodes). The antenna proposed for the above need was designed using HFSS, fabricated and was tested under ambient conditions. The rectenna provided a bandwidth of 512 MHz at the center frequency of 5.79 GHz (5725-5875MHz band) with a return loss of -18.7 dB. The system was found to provide a constant output of 6.1 millivolts. With the obtained results, it can be concluded that the proposed design can be successfully implemented for powering batteries in sensors used in 5G -IoT communications.