Authors:
Tomohiko Mitani
;
Takuya Ichihara
;
Nozomu Suzuki
and
Naoki Shinohara
Affiliation:
Research Institute for Sustainable Humanosphere, Kyoto University, Japan
Keyword(s):
Wireless power transmission, ZigBee, Wireless sensor network
Abstract:
The objective of the present study is to drive or charge a ZigBee device wirelessly by microwave power transmission. Wireless sensor network is expected to monitor several systems in order to control various
infrastructures, such as electric power consumption, actively. However, power supply for sensor terminals is a critical problem to realize a fruitful wireless sensor network system. Primary batteries needs to be changed
soon or later, wired power supply confines their installation location, and natural energy utilization like solar cells limits their regular operation. We therefore suggest wireless power supply for the sensor
terminals by microwave power transmission. We adopt a ZigBee device as a wireless sensor terminal because of its low power consumption. We experimentally investigated electromagnetic compatibility
between ZigBee and microwave power transmission, and found that there were some frequencies and power levels of microwave power transmission not to interrupt ZigBe
e. We also developed a microwave power
receiving system which consists of a receiving antenna, a rectification circuit, a dc-dc converter, and a power storage circuit or a secondary battery. Finally we succeeded establishment of ZigBee network while
driving a ZigBee device without batteries by microwave power transmission. Through the experiments, we found out intermittent microwave power transmission was preferable to CW microwave power transmission
with respect to electromagnetic compatibility and rf-dc efficiency.
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