Power Supply to Multiple Sensors and Leakage Field Analysis Using Cavity Resonance-Enabled Wireless Power Transfer

The purpose of this study is to apply simultaneous power supply to multiple sensors located in a greenhouse using cavity resonance-enabled wireless power transfer. The cavity has a gable-roof structure with width of 1500 mm, depth of 1800 mm, and height of 1960 mm, which is large enough to accommodate one person, and it is composed of metal meshes with a mesh spacing of 12.5 mm and a mesh wire diameter of 1 mm. Using this cavity, we demonstrate the simultaneous power supply to 10 power-receiving modules. When the input power is 2 W, at least 8.7 mW of power is supplied to each power-receiving module. In addition, we demonstrate that wired and wireless communication devices can be available during wireless power transmission. The maximum leakage electric field from the cavity is 0.95 V/m at the input power of 5 W, which follows the value of radio protection guidelines.