Energy Harvesting using 2.45GHz Rectenna for Powering Sensors in IoT Devices

Radio frequency energy transfer and harvesting techniques have recently become alternative methods to power the next generation wireless networks. The global move towards wireless access point (AP) densification has alluded towards the possibility of harvesting the unused ambient RF energy, especially in the industrial, scientific and medical band (ISM), in order to power useful electronic devices which collectively make up the so called low energy internet of things (LEIoT). Radio frequency process heating, microwave oven, medical diathermy machines, cordless phones, Bluetooth devices, near field communication devices, garage door openers, baby monitors and wireless computer devices uses the ISM frequencies. These untapped sources of energy grow more and more as a result of the rapid growth in the wireless communication business hence, there is a need to find a new method and means of collecting the ambient RF energy present in the environment and transforming that energy into electrical power. So backing this need a 2.45GHz rectenna based RF energy harvester for powering sensors in IoT devices is designed. Here a 2.45GHz antenna is integrated with rectifier to form the rectenna. The antenna consists of a rectangular patch embedded with feed line designed using the inset feeding technique using the EM simulation tool. By proper port matching good return loss is achieved with reasonable gain and diversity (of the antenna), DC voltage and power (of the rectenna) are analyzed from the simulated results.