An automatic polarization switching antenna structure for batteryless IoT devices

Abstract

Microwave power transmission (MPT) has many advantages. However, previous studies have indicated that MPT interferes with wireless data communication. In this paper, an adaptive polarization switchable rectenna architecture is proposed for simultaneous wireless information and power transfer. When the rectenna is activated by a wireless energy transmitter, the antenna automatically switches to another quadrature polarization state for wireless data communication. The experimental results show that the adaptive switching characteristic provides a wireless channel isolation of more than 23 dB between wireless power transfer and data communication. In a practical indoor environment, the measurement of packet error rate of the communication link shows that the power level of MPT could be increased by 16 dB and still keep the wireless connectivity. Thus, the proposed design is suitable for devices powered by MPT and for simultaneous wireless information and power transfer applications.