Circularly Polarized DR-Rectenna for 5G and Wi-Fi Bands RF Energy Harvesting in Smart City Applications

A smart city necessitates spectrum and energy efficiency with increasing applications which demand an increasing number of nodes in the Internet of Things (IoT) system networks. In recent years, radio frequency (RF) energy harvesting is best suited to enhance the energy efficiency required for self-sustained IoT networks incorporated in smart cities. This work proposes a rectangular dielectric resonator antenna (RDRA), that comprises a rectangular dielectric resonator (DR) and slots loaded ground plane. The proposed antenna operates efficiently at 3.5 and 5.8 GHz frequencies and also achieves circularly polarized characteristics at two operating bands. A microstrip feeding approach opts for excitation of the proposed antenna. The radiational properties of the proposed antenna show that the antenna is suitable to operate for radio frequency energy harvesting in smart city applications efficiently. An HSMS2860 Schottky diode has been chosen for the rectification at two bands of frequencies. A proper impedance matching is achieved using microstrip transmission lines and rectangular stubs connected to the rectifier circuit. The proposed rectifier circuit offers the maximum power conversion efficiency (PCE) of 54.53% and 41.26% at 3.5 and 5.8 GHz frequencies respectively for 5 dBm input power. The output voltages obtained at two frequencies are 1.31 V and 1.16 V, respectively.