Passive RF Energy Harvesting Scheme For Wireless Sensor

A radio frequency energy harvester harvests RF energy from the environment. The energy harvester may include a local power source. The energy harvester may have an associated crystal radio antenna that harvests AM radio waves ubiquitously. The radio frequency energy harvested may be stored via a super capacitor. The stored energy may power a self-contained processing unit directly when the level of the energy harvested remains above a threshold level. However, if the energy harvested drops below the threshold level, the processing unit, which may include a radio, may switch to the local power source and/or a low power mode of operation. The low power mode of operation may reduce the amount of processing and/or transmitting by the radio. The processing unit may be part of a network of radios. The energy harvester may supply energy for a variety of applications, including building automation, industrial automation, power generation, and healthcare.