Polarization modulation RF power transport for sensor network

As the interest in Internet of Things (IoT) has increased, supplying power to sensor nodes and sensor actuator has emerged to a key problem. To solve the issue, an active study of activating sensor nodes by receiving power from a specific power source wirelessly has been on progress. In particular, transmitting and receiving RF power seems to be the prime power transport technique to realize the next generation internet. In order to transmit and receive power efficiently, the polarization direction of both transmit and receive antenna should be the same. Since the receive antenna of the sensor nodes may have a random polarization direction depending on its installation, the transmit antenna should be able to change its polarization for uniform operation of every sensors in a sensor network without any failure. For this need, this paper suggests a modulation technique and a transmit antenna system which can generate 4 types(vertical (90°), horizontal (0°), 45°, 135°) of linear polarization.