Near-field wireless communication with no battery

Renesas Electronics Corp has developed a near-field wireless communication technology that can transmit data to Bluetooth- and wireless LAN-compatible devices without the use of a battery. The system instead makes use of the electricity generated by environmental radio waves. Since the system does not require a battery, it has the capability of being used to create an ultra-small sensor node that could be used in a variety of applications and send data to a smart phone that is within a distance of one meter. The system could also be used with any Bluetooth-compatible device in range. This is possible because the system reduces the use of power from several tens of milliwatts to several microwatts, which represents a significant decrease in power. The system is equipped with an LC resonant circuit. The circuit allows the system to absorb radio waves through LC resonance. The harvesting occurs at a rate of about 10μW from environmental radio waves. The radio waves can then be used to transmit the signal to mobile devices, allowing them to interpret the device as the sensor node sending “0 ” signals when it is on and “1 ” signals when the device is not transmitting.