RF Radiation

RF Radiation
RF radiation is employed to power ID cards by directing high power electromagnetic energy to the devices from a nearby source. In addition to energy, it is possible to send information as well. However, the term energy harvesting implies that it is the same device which gets its energy from the environment. In cities and very populated areas there is a large number of potential RF sources: broadcast radio and tv, mobile telephony, wireless networks, etc. The problem is collecting all these disparate sources and converting them in useful energy. The conversion is based on a rectifying antenna (rectenna), constructed with a Schottky diode located between the antenna dipoles. The energy levels actually present are so low that no present electronic device can use them. However, future technologies may allow the fabrication of lower power devices that would “recycle” RF energy generated for other purposes by different elements