Background and description
Wireless sensors, which transmit the collected information without the need of wiring, have gained increasing commercial importance. These sensors can be used in a wide range of situations, from environmental monitoring to farm and industrial control. However, most sensors still need to use batteries, which increases maintenance and environmental costs.
The presented sensors are an alternative since they do not require any type of battery and receive energy through a specific frequency emitted by an energy transmitter. These passive sensors gain even more relevance if sensor networks are formed, in which several nearby sensors detect and transmit environmental data. These sensors can have the capability of reusing ambient electromagnetic waves to perform the communication (e.g. Wi-Fi, Blue-tooth, LoRa, etc.).