Greinacher Rectifier Evaluation for WiFi Band Energy Harvesting

Wireless sensor networks (WSN) have significantly developed in recent years and are highly interested in acquiring data from remote systems. These networks require the availability of sensors with autonomy and low power consumption. Autonomous energization focuses on recycling and optimizing energy sources whose principle of use is based on specific characteristics of the environment and which are not conventionally used. One alternative, with great potential, is the recycling of electromagnetic energy, which is radiated by WiFi internet connection equipment currently found almost everywhere, capturing and using them as sources of electrical energy. The main element is the power converter that captures radio frequency energy radiated by access points of a WiFi network and generates electrical energy. This paper evaluates the potential of the Greinacher rectifier and three circuit variants. The rectifier is popular because of its low power consumption. The energy capture is performed with a commercial omnidirectional antenna tuned to 2.4 GHz. The rectifier is evaluated in two scenarios. Results verify that it is possible to obtain a voltage of up to 1.4 [V] and energize a 20 [mA] LED for 1.2 [s] after a charging time of approximately 24 [h], information that can be used for the development of autonomous energization circuits in WSN.